<?xml version="1.0" encoding="UTF-8"?>
<dataset name="atmospheric_methane" title="Atmospheric methane (CH₄), global monthly mean" source="https://aidb.si/d/atmospheric-methane">
  <row>
    <month>1983-07</month>
    <year>1983</year>
    <decimal_date>1983.542</decimal_date>
    <ch4_ppb>1625.96</ch4_ppb>
    <ch4_trend_ppb>1635.11</ch4_trend_ppb>
    <uncertainty>2.25</uncertainty>
    <trend_uncertainty>1.5</trend_uncertainty>
  </row>
  <row>
    <month>1983-08</month>
    <year>1983</year>
    <decimal_date>1983.625</decimal_date>
    <ch4_ppb>1628.04</ch4_ppb>
    <ch4_trend_ppb>1635.61</ch4_trend_ppb>
    <uncertainty>2.83</uncertainty>
    <trend_uncertainty>1.44</trend_uncertainty>
  </row>
  <row>
    <month>1983-09</month>
    <year>1983</year>
    <decimal_date>1983.708</decimal_date>
    <ch4_ppb>1638.44</ch4_ppb>
    <ch4_trend_ppb>1636.17</ch4_trend_ppb>
    <uncertainty>2.45</uncertainty>
    <trend_uncertainty>1.36</trend_uncertainty>
  </row>
  <row>
    <month>1983-10</month>
    <year>1983</year>
    <decimal_date>1983.792</decimal_date>
    <ch4_ppb>1644.8</ch4_ppb>
    <ch4_trend_ppb>1636.81</ch4_trend_ppb>
    <uncertainty>1.58</uncertainty>
    <trend_uncertainty>1.27</trend_uncertainty>
  </row>
  <row>
    <month>1983-11</month>
    <year>1983</year>
    <decimal_date>1983.875</decimal_date>
    <ch4_ppb>1642.59</ch4_ppb>
    <ch4_trend_ppb>1637.51</ch4_trend_ppb>
    <uncertainty>0.79</uncertainty>
    <trend_uncertainty>1.18</trend_uncertainty>
  </row>
  <row>
    <month>1983-12</month>
    <year>1983</year>
    <decimal_date>1983.958</decimal_date>
    <ch4_ppb>1639.55</ch4_ppb>
    <ch4_trend_ppb>1638.3</ch4_trend_ppb>
    <uncertainty>0.89</uncertainty>
    <trend_uncertainty>1.08</trend_uncertainty>
  </row>
  <row>
    <month>1984-01</month>
    <year>1984</year>
    <decimal_date>1984.042</decimal_date>
    <ch4_ppb>1638.73</ch4_ppb>
    <ch4_trend_ppb>1639.17</ch4_trend_ppb>
    <uncertainty>2</uncertainty>
    <trend_uncertainty>0.97</trend_uncertainty>
  </row>
  <row>
    <month>1984-02</month>
    <year>1984</year>
    <decimal_date>1984.125</decimal_date>
    <ch4_ppb>1638.81</ch4_ppb>
    <ch4_trend_ppb>1640.08</ch4_trend_ppb>
    <uncertainty>2.03</uncertainty>
    <trend_uncertainty>0.88</trend_uncertainty>
  </row>
  <row>
    <month>1984-03</month>
    <year>1984</year>
    <decimal_date>1984.208</decimal_date>
    <ch4_ppb>1640.87</ch4_ppb>
    <ch4_trend_ppb>1641.05</ch4_trend_ppb>
    <uncertainty>1.76</uncertainty>
    <trend_uncertainty>0.8</trend_uncertainty>
  </row>
  <row>
    <month>1984-04</month>
    <year>1984</year>
    <decimal_date>1984.292</decimal_date>
    <ch4_ppb>1643.96</ch4_ppb>
    <ch4_trend_ppb>1642.1</ch4_trend_ppb>
    <uncertainty>2.12</uncertainty>
    <trend_uncertainty>0.72</trend_uncertainty>
  </row>
  <row>
    <month>1984-05</month>
    <year>1984</year>
    <decimal_date>1984.375</decimal_date>
    <ch4_ppb>1643.14</ch4_ppb>
    <ch4_trend_ppb>1643.19</ch4_trend_ppb>
    <uncertainty>1.12</uncertainty>
    <trend_uncertainty>0.65</trend_uncertainty>
  </row>
  <row>
    <month>1984-06</month>
    <year>1984</year>
    <decimal_date>1984.458</decimal_date>
    <ch4_ppb>1639.75</ch4_ppb>
    <ch4_trend_ppb>1644.3</ch4_trend_ppb>
    <uncertainty>0.77</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>1984-07</month>
    <year>1984</year>
    <decimal_date>1984.542</decimal_date>
    <ch4_ppb>1637.98</ch4_ppb>
    <ch4_trend_ppb>1645.44</ch4_trend_ppb>
    <uncertainty>0.88</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>1984-08</month>
    <year>1984</year>
    <decimal_date>1984.625</decimal_date>
    <ch4_ppb>1641.69</ch4_ppb>
    <ch4_trend_ppb>1646.61</ch4_trend_ppb>
    <uncertainty>1.3</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>1984-09</month>
    <year>1984</year>
    <decimal_date>1984.708</decimal_date>
    <ch4_ppb>1650.64</ch4_ppb>
    <ch4_trend_ppb>1647.75</ch4_trend_ppb>
    <uncertainty>0.95</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>1984-10</month>
    <year>1984</year>
    <decimal_date>1984.792</decimal_date>
    <ch4_ppb>1654.59</ch4_ppb>
    <ch4_trend_ppb>1648.88</ch4_trend_ppb>
    <uncertainty>1.28</uncertainty>
    <trend_uncertainty>0.52</trend_uncertainty>
  </row>
  <row>
    <month>1984-11</month>
    <year>1984</year>
    <decimal_date>1984.875</decimal_date>
    <ch4_ppb>1653.77</ch4_ppb>
    <ch4_trend_ppb>1649.99</ch4_trend_ppb>
    <uncertainty>0.97</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
  </row>
  <row>
    <month>1984-12</month>
    <year>1984</year>
    <decimal_date>1984.958</decimal_date>
    <ch4_ppb>1656.21</ch4_ppb>
    <ch4_trend_ppb>1651.08</ch4_trend_ppb>
    <uncertainty>1.23</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
  </row>
  <row>
    <month>1985-01</month>
    <year>1985</year>
    <decimal_date>1985.042</decimal_date>
    <ch4_ppb>1655.59</ch4_ppb>
    <ch4_trend_ppb>1652.17</ch4_trend_ppb>
    <uncertainty>1.17</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>1985-02</month>
    <year>1985</year>
    <decimal_date>1985.125</decimal_date>
    <ch4_ppb>1652.23</ch4_ppb>
    <ch4_trend_ppb>1653.18</ch4_trend_ppb>
    <uncertainty>1.43</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>1985-03</month>
    <year>1985</year>
    <decimal_date>1985.208</decimal_date>
    <ch4_ppb>1654.62</ch4_ppb>
    <ch4_trend_ppb>1654.18</ch4_trend_ppb>
    <uncertainty>0.93</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>1985-04</month>
    <year>1985</year>
    <decimal_date>1985.292</decimal_date>
    <ch4_ppb>1658.19</ch4_ppb>
    <ch4_trend_ppb>1655.19</ch4_trend_ppb>
    <uncertainty>0.8</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>1985-05</month>
    <year>1985</year>
    <decimal_date>1985.375</decimal_date>
    <ch4_ppb>1655.87</ch4_ppb>
    <ch4_trend_ppb>1656.19</ch4_trend_ppb>
    <uncertainty>1.18</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
  </row>
  <row>
    <month>1985-06</month>
    <year>1985</year>
    <decimal_date>1985.458</decimal_date>
    <ch4_ppb>1650.07</ch4_ppb>
    <ch4_trend_ppb>1657.19</ch4_trend_ppb>
    <uncertainty>1.32</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>1985-07</month>
    <year>1985</year>
    <decimal_date>1985.542</decimal_date>
    <ch4_ppb>1646.8</ch4_ppb>
    <ch4_trend_ppb>1658.19</ch4_trend_ppb>
    <uncertainty>1.15</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>1985-08</month>
    <year>1985</year>
    <decimal_date>1985.625</decimal_date>
    <ch4_ppb>1652.24</ch4_ppb>
    <ch4_trend_ppb>1659.2</ch4_trend_ppb>
    <uncertainty>1.19</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>1985-09</month>
    <year>1985</year>
    <decimal_date>1985.708</decimal_date>
    <ch4_ppb>1662.51</ch4_ppb>
    <ch4_trend_ppb>1660.21</ch4_trend_ppb>
    <uncertainty>1.23</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>1985-10</month>
    <year>1985</year>
    <decimal_date>1985.792</decimal_date>
    <ch4_ppb>1667.49</ch4_ppb>
    <ch4_trend_ppb>1661.22</ch4_trend_ppb>
    <uncertainty>1.06</uncertainty>
    <trend_uncertainty>0.63</trend_uncertainty>
  </row>
  <row>
    <month>1985-11</month>
    <year>1985</year>
    <decimal_date>1985.875</decimal_date>
    <ch4_ppb>1666.8</ch4_ppb>
    <ch4_trend_ppb>1662.25</ch4_trend_ppb>
    <uncertainty>1.07</uncertainty>
    <trend_uncertainty>0.65</trend_uncertainty>
  </row>
  <row>
    <month>1985-12</month>
    <year>1985</year>
    <decimal_date>1985.958</decimal_date>
    <ch4_ppb>1666.07</ch4_ppb>
    <ch4_trend_ppb>1663.28</ch4_trend_ppb>
    <uncertainty>1.06</uncertainty>
    <trend_uncertainty>0.68</trend_uncertainty>
  </row>
  <row>
    <month>1986-01</month>
    <year>1986</year>
    <decimal_date>1986.042</decimal_date>
    <ch4_ppb>1666.29</ch4_ppb>
    <ch4_trend_ppb>1664.34</ch4_trend_ppb>
    <uncertainty>1.2</uncertainty>
    <trend_uncertainty>0.71</trend_uncertainty>
  </row>
  <row>
    <month>1986-02</month>
    <year>1986</year>
    <decimal_date>1986.125</decimal_date>
    <ch4_ppb>1666.92</ch4_ppb>
    <ch4_trend_ppb>1665.36</ch4_trend_ppb>
    <uncertainty>1.75</uncertainty>
    <trend_uncertainty>0.73</trend_uncertainty>
  </row>
  <row>
    <month>1986-03</month>
    <year>1986</year>
    <decimal_date>1986.208</decimal_date>
    <ch4_ppb>1669.27</ch4_ppb>
    <ch4_trend_ppb>1666.38</ch4_trend_ppb>
    <uncertainty>1.49</uncertainty>
    <trend_uncertainty>0.75</trend_uncertainty>
  </row>
  <row>
    <month>1986-04</month>
    <year>1986</year>
    <decimal_date>1986.292</decimal_date>
    <ch4_ppb>1670.8</ch4_ppb>
    <ch4_trend_ppb>1667.45</ch4_trend_ppb>
    <uncertainty>1.5</uncertainty>
    <trend_uncertainty>0.76</trend_uncertainty>
  </row>
  <row>
    <month>1986-05</month>
    <year>1986</year>
    <decimal_date>1986.375</decimal_date>
    <ch4_ppb>1668.45</ch4_ppb>
    <ch4_trend_ppb>1668.52</ch4_trend_ppb>
    <uncertainty>0.94</uncertainty>
    <trend_uncertainty>0.78</trend_uncertainty>
  </row>
  <row>
    <month>1986-06</month>
    <year>1986</year>
    <decimal_date>1986.458</decimal_date>
    <ch4_ppb>1664.78</ch4_ppb>
    <ch4_trend_ppb>1669.6</ch4_trend_ppb>
    <uncertainty>1.18</uncertainty>
    <trend_uncertainty>0.78</trend_uncertainty>
  </row>
  <row>
    <month>1986-07</month>
    <year>1986</year>
    <decimal_date>1986.542</decimal_date>
    <ch4_ppb>1662.32</ch4_ppb>
    <ch4_trend_ppb>1670.68</ch4_trend_ppb>
    <uncertainty>1.13</uncertainty>
    <trend_uncertainty>0.79</trend_uncertainty>
  </row>
  <row>
    <month>1986-08</month>
    <year>1986</year>
    <decimal_date>1986.625</decimal_date>
    <ch4_ppb>1664.37</ch4_ppb>
    <ch4_trend_ppb>1671.79</ch4_trend_ppb>
    <uncertainty>1.64</uncertainty>
    <trend_uncertainty>0.79</trend_uncertainty>
  </row>
  <row>
    <month>1986-09</month>
    <year>1986</year>
    <decimal_date>1986.708</decimal_date>
    <ch4_ppb>1672.59</ch4_ppb>
    <ch4_trend_ppb>1672.88</ch4_trend_ppb>
    <uncertainty>1.51</uncertainty>
    <trend_uncertainty>0.78</trend_uncertainty>
  </row>
  <row>
    <month>1986-10</month>
    <year>1986</year>
    <decimal_date>1986.792</decimal_date>
    <ch4_ppb>1678.67</ch4_ppb>
    <ch4_trend_ppb>1673.97</ch4_trend_ppb>
    <uncertainty>1.46</uncertainty>
    <trend_uncertainty>0.76</trend_uncertainty>
  </row>
  <row>
    <month>1986-11</month>
    <year>1986</year>
    <decimal_date>1986.875</decimal_date>
    <ch4_ppb>1678.97</ch4_ppb>
    <ch4_trend_ppb>1675.06</ch4_trend_ppb>
    <uncertainty>1.59</uncertainty>
    <trend_uncertainty>0.75</trend_uncertainty>
  </row>
  <row>
    <month>1986-12</month>
    <year>1986</year>
    <decimal_date>1986.958</decimal_date>
    <ch4_ppb>1679.14</ch4_ppb>
    <ch4_trend_ppb>1676.15</ch4_trend_ppb>
    <uncertainty>0.99</uncertainty>
    <trend_uncertainty>0.73</trend_uncertainty>
  </row>
  <row>
    <month>1987-01</month>
    <year>1987</year>
    <decimal_date>1987.042</decimal_date>
    <ch4_ppb>1679.42</ch4_ppb>
    <ch4_trend_ppb>1677.25</ch4_trend_ppb>
    <uncertainty>1.15</uncertainty>
    <trend_uncertainty>0.7</trend_uncertainty>
  </row>
  <row>
    <month>1987-02</month>
    <year>1987</year>
    <decimal_date>1987.125</decimal_date>
    <ch4_ppb>1679.02</ch4_ppb>
    <ch4_trend_ppb>1678.29</ch4_trend_ppb>
    <uncertainty>1.1</uncertainty>
    <trend_uncertainty>0.67</trend_uncertainty>
  </row>
  <row>
    <month>1987-03</month>
    <year>1987</year>
    <decimal_date>1987.208</decimal_date>
    <ch4_ppb>1680.02</ch4_ppb>
    <ch4_trend_ppb>1679.31</ch4_trend_ppb>
    <uncertainty>0.94</uncertainty>
    <trend_uncertainty>0.64</trend_uncertainty>
  </row>
  <row>
    <month>1987-04</month>
    <year>1987</year>
    <decimal_date>1987.292</decimal_date>
    <ch4_ppb>1681.36</ch4_ppb>
    <ch4_trend_ppb>1680.35</ch4_trend_ppb>
    <uncertainty>0.94</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>1987-05</month>
    <year>1987</year>
    <decimal_date>1987.375</decimal_date>
    <ch4_ppb>1681.86</ch4_ppb>
    <ch4_trend_ppb>1681.37</ch4_trend_ppb>
    <uncertainty>0.95</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>1987-06</month>
    <year>1987</year>
    <decimal_date>1987.458</decimal_date>
    <ch4_ppb>1680</ch4_ppb>
    <ch4_trend_ppb>1682.36</ch4_trend_ppb>
    <uncertainty>1.12</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>1987-07</month>
    <year>1987</year>
    <decimal_date>1987.542</decimal_date>
    <ch4_ppb>1675.97</ch4_ppb>
    <ch4_trend_ppb>1683.32</ch4_trend_ppb>
    <uncertainty>0.93</uncertainty>
    <trend_uncertainty>0.52</trend_uncertainty>
  </row>
  <row>
    <month>1987-08</month>
    <year>1987</year>
    <decimal_date>1987.625</decimal_date>
    <ch4_ppb>1677.19</ch4_ppb>
    <ch4_trend_ppb>1684.27</ch4_trend_ppb>
    <uncertainty>0.85</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>1987-09</month>
    <year>1987</year>
    <decimal_date>1987.708</decimal_date>
    <ch4_ppb>1685.61</ch4_ppb>
    <ch4_trend_ppb>1685.17</ch4_trend_ppb>
    <uncertainty>1.07</uncertainty>
    <trend_uncertainty>0.47</trend_uncertainty>
  </row>
  <row>
    <month>1987-10</month>
    <year>1987</year>
    <decimal_date>1987.792</decimal_date>
    <ch4_ppb>1691.54</ch4_ppb>
    <ch4_trend_ppb>1686.04</ch4_trend_ppb>
    <uncertainty>1.02</uncertainty>
    <trend_uncertainty>0.46</trend_uncertainty>
  </row>
  <row>
    <month>1987-11</month>
    <year>1987</year>
    <decimal_date>1987.875</decimal_date>
    <ch4_ppb>1691.18</ch4_ppb>
    <ch4_trend_ppb>1686.89</ch4_trend_ppb>
    <uncertainty>0.86</uncertainty>
    <trend_uncertainty>0.45</trend_uncertainty>
  </row>
  <row>
    <month>1987-12</month>
    <year>1987</year>
    <decimal_date>1987.958</decimal_date>
    <ch4_ppb>1690.53</ch4_ppb>
    <ch4_trend_ppb>1687.72</ch4_trend_ppb>
    <uncertainty>0.88</uncertainty>
    <trend_uncertainty>0.44</trend_uncertainty>
  </row>
  <row>
    <month>1988-01</month>
    <year>1988</year>
    <decimal_date>1988.042</decimal_date>
    <ch4_ppb>1691.98</ch4_ppb>
    <ch4_trend_ppb>1688.55</ch4_trend_ppb>
    <uncertainty>0.91</uncertainty>
    <trend_uncertainty>0.45</trend_uncertainty>
  </row>
  <row>
    <month>1988-02</month>
    <year>1988</year>
    <decimal_date>1988.125</decimal_date>
    <ch4_ppb>1692.53</ch4_ppb>
    <ch4_trend_ppb>1689.35</ch4_trend_ppb>
    <uncertainty>0.93</uncertainty>
    <trend_uncertainty>0.47</trend_uncertainty>
  </row>
  <row>
    <month>1988-03</month>
    <year>1988</year>
    <decimal_date>1988.208</decimal_date>
    <ch4_ppb>1691.3</ch4_ppb>
    <ch4_trend_ppb>1690.15</ch4_trend_ppb>
    <uncertainty>1.12</uncertainty>
    <trend_uncertainty>0.49</trend_uncertainty>
  </row>
  <row>
    <month>1988-04</month>
    <year>1988</year>
    <decimal_date>1988.292</decimal_date>
    <ch4_ppb>1690.05</ch4_ppb>
    <ch4_trend_ppb>1690.97</ch4_trend_ppb>
    <uncertainty>1.08</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>1988-05</month>
    <year>1988</year>
    <decimal_date>1988.375</decimal_date>
    <ch4_ppb>1689.1</ch4_ppb>
    <ch4_trend_ppb>1691.81</ch4_trend_ppb>
    <uncertainty>0.98</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>1988-06</month>
    <year>1988</year>
    <decimal_date>1988.458</decimal_date>
    <ch4_ppb>1687.2</ch4_ppb>
    <ch4_trend_ppb>1692.67</ch4_trend_ppb>
    <uncertainty>1.18</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>1988-07</month>
    <year>1988</year>
    <decimal_date>1988.542</decimal_date>
    <ch4_ppb>1686.01</ch4_ppb>
    <ch4_trend_ppb>1693.55</ch4_trend_ppb>
    <uncertainty>0.79</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>1988-08</month>
    <year>1988</year>
    <decimal_date>1988.625</decimal_date>
    <ch4_ppb>1689.44</ch4_ppb>
    <ch4_trend_ppb>1694.48</ch4_trend_ppb>
    <uncertainty>0.85</uncertainty>
    <trend_uncertainty>0.64</trend_uncertainty>
  </row>
  <row>
    <month>1988-09</month>
    <year>1988</year>
    <decimal_date>1988.708</decimal_date>
    <ch4_ppb>1696.14</ch4_ppb>
    <ch4_trend_ppb>1695.41</ch4_trend_ppb>
    <uncertainty>0.98</uncertainty>
    <trend_uncertainty>0.66</trend_uncertainty>
  </row>
  <row>
    <month>1988-10</month>
    <year>1988</year>
    <decimal_date>1988.792</decimal_date>
    <ch4_ppb>1701.13</ch4_ppb>
    <ch4_trend_ppb>1696.37</ch4_trend_ppb>
    <uncertainty>1.34</uncertainty>
    <trend_uncertainty>0.67</trend_uncertainty>
  </row>
  <row>
    <month>1988-11</month>
    <year>1988</year>
    <decimal_date>1988.875</decimal_date>
    <ch4_ppb>1702.83</ch4_ppb>
    <ch4_trend_ppb>1697.35</ch4_trend_ppb>
    <uncertainty>1.48</uncertainty>
    <trend_uncertainty>0.67</trend_uncertainty>
  </row>
  <row>
    <month>1988-12</month>
    <year>1988</year>
    <decimal_date>1988.958</decimal_date>
    <ch4_ppb>1701.92</ch4_ppb>
    <ch4_trend_ppb>1698.35</ch4_trend_ppb>
    <uncertainty>1.21</uncertainty>
    <trend_uncertainty>0.67</trend_uncertainty>
  </row>
  <row>
    <month>1989-01</month>
    <year>1989</year>
    <decimal_date>1989.042</decimal_date>
    <ch4_ppb>1700.54</ch4_ppb>
    <ch4_trend_ppb>1699.37</ch4_trend_ppb>
    <uncertainty>1.1</uncertainty>
    <trend_uncertainty>0.65</trend_uncertainty>
  </row>
  <row>
    <month>1989-02</month>
    <year>1989</year>
    <decimal_date>1989.125</decimal_date>
    <ch4_ppb>1701.11</ch4_ppb>
    <ch4_trend_ppb>1700.36</ch4_trend_ppb>
    <uncertainty>1.25</uncertainty>
    <trend_uncertainty>0.64</trend_uncertainty>
  </row>
  <row>
    <month>1989-03</month>
    <year>1989</year>
    <decimal_date>1989.208</decimal_date>
    <ch4_ppb>1702.5</ch4_ppb>
    <ch4_trend_ppb>1701.34</ch4_trend_ppb>
    <uncertainty>1.21</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>1989-04</month>
    <year>1989</year>
    <decimal_date>1989.292</decimal_date>
    <ch4_ppb>1703.57</ch4_ppb>
    <ch4_trend_ppb>1702.35</ch4_trend_ppb>
    <uncertainty>0.98</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>1989-05</month>
    <year>1989</year>
    <decimal_date>1989.375</decimal_date>
    <ch4_ppb>1703.35</ch4_ppb>
    <ch4_trend_ppb>1703.34</ch4_trend_ppb>
    <uncertainty>0.56</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>1989-06</month>
    <year>1989</year>
    <decimal_date>1989.458</decimal_date>
    <ch4_ppb>1700.22</ch4_ppb>
    <ch4_trend_ppb>1704.32</ch4_trend_ppb>
    <uncertainty>0.8</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>1989-07</month>
    <year>1989</year>
    <decimal_date>1989.542</decimal_date>
    <ch4_ppb>1698.19</ch4_ppb>
    <ch4_trend_ppb>1705.27</ch4_trend_ppb>
    <uncertainty>0.9</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>1989-08</month>
    <year>1989</year>
    <decimal_date>1989.625</decimal_date>
    <ch4_ppb>1701.96</ch4_ppb>
    <ch4_trend_ppb>1706.22</ch4_trend_ppb>
    <uncertainty>1.01</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>1989-09</month>
    <year>1989</year>
    <decimal_date>1989.708</decimal_date>
    <ch4_ppb>1707.19</ch4_ppb>
    <ch4_trend_ppb>1707.12</ch4_trend_ppb>
    <uncertainty>0.91</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>1989-10</month>
    <year>1989</year>
    <decimal_date>1989.792</decimal_date>
    <ch4_ppb>1710.52</ch4_ppb>
    <ch4_trend_ppb>1707.99</ch4_trend_ppb>
    <uncertainty>0.9</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>1989-11</month>
    <year>1989</year>
    <decimal_date>1989.875</decimal_date>
    <ch4_ppb>1713.1</ch4_ppb>
    <ch4_trend_ppb>1708.83</ch4_trend_ppb>
    <uncertainty>0.85</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>1989-12</month>
    <year>1989</year>
    <decimal_date>1989.958</decimal_date>
    <ch4_ppb>1713.24</ch4_ppb>
    <ch4_trend_ppb>1709.63</ch4_trend_ppb>
    <uncertainty>0.86</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>1990-01</month>
    <year>1990</year>
    <decimal_date>1990.042</decimal_date>
    <ch4_ppb>1712.14</ch4_ppb>
    <ch4_trend_ppb>1710.42</ch4_trend_ppb>
    <uncertainty>1.13</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>1990-02</month>
    <year>1990</year>
    <decimal_date>1990.125</decimal_date>
    <ch4_ppb>1713.49</ch4_ppb>
    <ch4_trend_ppb>1711.13</ch4_trend_ppb>
    <uncertainty>1.18</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>1990-03</month>
    <year>1990</year>
    <decimal_date>1990.208</decimal_date>
    <ch4_ppb>1714.36</ch4_ppb>
    <ch4_trend_ppb>1711.82</ch4_trend_ppb>
    <uncertainty>0.99</uncertainty>
    <trend_uncertainty>0.64</trend_uncertainty>
  </row>
  <row>
    <month>1990-04</month>
    <year>1990</year>
    <decimal_date>1990.292</decimal_date>
    <ch4_ppb>1712.53</ch4_ppb>
    <ch4_trend_ppb>1712.5</ch4_trend_ppb>
    <uncertainty>1.04</uncertainty>
    <trend_uncertainty>0.66</trend_uncertainty>
  </row>
  <row>
    <month>1990-05</month>
    <year>1990</year>
    <decimal_date>1990.375</decimal_date>
    <ch4_ppb>1710.64</ch4_ppb>
    <ch4_trend_ppb>1713.17</ch4_trend_ppb>
    <uncertainty>0.97</uncertainty>
    <trend_uncertainty>0.67</trend_uncertainty>
  </row>
  <row>
    <month>1990-06</month>
    <year>1990</year>
    <decimal_date>1990.458</decimal_date>
    <ch4_ppb>1708.46</ch4_ppb>
    <ch4_trend_ppb>1713.83</ch4_trend_ppb>
    <uncertainty>0.71</uncertainty>
    <trend_uncertainty>0.69</trend_uncertainty>
  </row>
  <row>
    <month>1990-07</month>
    <year>1990</year>
    <decimal_date>1990.542</decimal_date>
    <ch4_ppb>1706.55</ch4_ppb>
    <ch4_trend_ppb>1714.49</ch4_trend_ppb>
    <uncertainty>0.66</uncertainty>
    <trend_uncertainty>0.69</trend_uncertainty>
  </row>
  <row>
    <month>1990-08</month>
    <year>1990</year>
    <decimal_date>1990.625</decimal_date>
    <ch4_ppb>1710.23</ch4_ppb>
    <ch4_trend_ppb>1715.17</ch4_trend_ppb>
    <uncertainty>1.3</uncertainty>
    <trend_uncertainty>0.69</trend_uncertainty>
  </row>
  <row>
    <month>1990-09</month>
    <year>1990</year>
    <decimal_date>1990.708</decimal_date>
    <ch4_ppb>1717.61</ch4_ppb>
    <ch4_trend_ppb>1715.87</ch4_trend_ppb>
    <uncertainty>1.32</uncertainty>
    <trend_uncertainty>0.69</trend_uncertainty>
  </row>
  <row>
    <month>1990-10</month>
    <year>1990</year>
    <decimal_date>1990.792</decimal_date>
    <ch4_ppb>1722.01</ch4_ppb>
    <ch4_trend_ppb>1716.6</ch4_trend_ppb>
    <uncertainty>1</uncertainty>
    <trend_uncertainty>0.69</trend_uncertainty>
  </row>
  <row>
    <month>1990-11</month>
    <year>1990</year>
    <decimal_date>1990.875</decimal_date>
    <ch4_ppb>1723.45</ch4_ppb>
    <ch4_trend_ppb>1717.39</ch4_trend_ppb>
    <uncertainty>0.9</uncertainty>
    <trend_uncertainty>0.68</trend_uncertainty>
  </row>
  <row>
    <month>1990-12</month>
    <year>1990</year>
    <decimal_date>1990.958</decimal_date>
    <ch4_ppb>1723.33</ch4_ppb>
    <ch4_trend_ppb>1718.24</ch4_trend_ppb>
    <uncertainty>1.08</uncertainty>
    <trend_uncertainty>0.68</trend_uncertainty>
  </row>
  <row>
    <month>1991-01</month>
    <year>1991</year>
    <decimal_date>1991.042</decimal_date>
    <ch4_ppb>1721.76</ch4_ppb>
    <ch4_trend_ppb>1719.18</ch4_trend_ppb>
    <uncertainty>1.14</uncertainty>
    <trend_uncertainty>0.67</trend_uncertainty>
  </row>
  <row>
    <month>1991-02</month>
    <year>1991</year>
    <decimal_date>1991.125</decimal_date>
    <ch4_ppb>1721.42</ch4_ppb>
    <ch4_trend_ppb>1720.15</ch4_trend_ppb>
    <uncertainty>1.02</uncertainty>
    <trend_uncertainty>0.67</trend_uncertainty>
  </row>
  <row>
    <month>1991-03</month>
    <year>1991</year>
    <decimal_date>1991.208</decimal_date>
    <ch4_ppb>1722.09</ch4_ppb>
    <ch4_trend_ppb>1721.19</ch4_trend_ppb>
    <uncertainty>0.93</uncertainty>
    <trend_uncertainty>0.67</trend_uncertainty>
  </row>
  <row>
    <month>1991-04</month>
    <year>1991</year>
    <decimal_date>1991.292</decimal_date>
    <ch4_ppb>1722.37</ch4_ppb>
    <ch4_trend_ppb>1722.34</ch4_trend_ppb>
    <uncertainty>1.1</uncertainty>
    <trend_uncertainty>0.68</trend_uncertainty>
  </row>
  <row>
    <month>1991-05</month>
    <year>1991</year>
    <decimal_date>1991.375</decimal_date>
    <ch4_ppb>1722.08</ch4_ppb>
    <ch4_trend_ppb>1723.56</ch4_trend_ppb>
    <uncertainty>1.1</uncertainty>
    <trend_uncertainty>0.68</trend_uncertainty>
  </row>
  <row>
    <month>1991-06</month>
    <year>1991</year>
    <decimal_date>1991.458</decimal_date>
    <ch4_ppb>1718.87</ch4_ppb>
    <ch4_trend_ppb>1724.83</ch4_trend_ppb>
    <uncertainty>1.08</uncertainty>
    <trend_uncertainty>0.69</trend_uncertainty>
  </row>
  <row>
    <month>1991-07</month>
    <year>1991</year>
    <decimal_date>1991.542</decimal_date>
    <ch4_ppb>1715.91</ch4_ppb>
    <ch4_trend_ppb>1726.13</ch4_trend_ppb>
    <uncertainty>0.92</uncertainty>
    <trend_uncertainty>0.7</trend_uncertainty>
  </row>
  <row>
    <month>1991-08</month>
    <year>1991</year>
    <decimal_date>1991.625</decimal_date>
    <ch4_ppb>1719.05</ch4_ppb>
    <ch4_trend_ppb>1727.46</ch4_trend_ppb>
    <uncertainty>1.12</uncertainty>
    <trend_uncertainty>0.7</trend_uncertainty>
  </row>
  <row>
    <month>1991-09</month>
    <year>1991</year>
    <decimal_date>1991.708</decimal_date>
    <ch4_ppb>1726.04</ch4_ppb>
    <ch4_trend_ppb>1728.75</ch4_trend_ppb>
    <uncertainty>1.64</uncertainty>
    <trend_uncertainty>0.71</trend_uncertainty>
  </row>
  <row>
    <month>1991-10</month>
    <year>1991</year>
    <decimal_date>1991.792</decimal_date>
    <ch4_ppb>1732.78</ch4_ppb>
    <ch4_trend_ppb>1729.98</ch4_trend_ppb>
    <uncertainty>0.99</uncertainty>
    <trend_uncertainty>0.71</trend_uncertainty>
  </row>
  <row>
    <month>1991-11</month>
    <year>1991</year>
    <decimal_date>1991.875</decimal_date>
    <ch4_ppb>1737.52</ch4_ppb>
    <ch4_trend_ppb>1731.14</ch4_trend_ppb>
    <uncertainty>0.88</uncertainty>
    <trend_uncertainty>0.7</trend_uncertainty>
  </row>
  <row>
    <month>1991-12</month>
    <year>1991</year>
    <decimal_date>1991.958</decimal_date>
    <ch4_ppb>1739.58</ch4_ppb>
    <ch4_trend_ppb>1732.2</ch4_trend_ppb>
    <uncertainty>1.05</uncertainty>
    <trend_uncertainty>0.69</trend_uncertainty>
  </row>
  <row>
    <month>1992-01</month>
    <year>1992</year>
    <decimal_date>1992.042</decimal_date>
    <ch4_ppb>1738.91</ch4_ppb>
    <ch4_trend_ppb>1733.14</ch4_trend_ppb>
    <uncertainty>1.11</uncertainty>
    <trend_uncertainty>0.68</trend_uncertainty>
  </row>
  <row>
    <month>1992-02</month>
    <year>1992</year>
    <decimal_date>1992.125</decimal_date>
    <ch4_ppb>1737.31</ch4_ppb>
    <ch4_trend_ppb>1733.91</ch4_trend_ppb>
    <uncertainty>1.16</uncertainty>
    <trend_uncertainty>0.66</trend_uncertainty>
  </row>
  <row>
    <month>1992-03</month>
    <year>1992</year>
    <decimal_date>1992.208</decimal_date>
    <ch4_ppb>1736.81</ch4_ppb>
    <ch4_trend_ppb>1734.53</ch4_trend_ppb>
    <uncertainty>0.91</uncertainty>
    <trend_uncertainty>0.64</trend_uncertainty>
  </row>
  <row>
    <month>1992-04</month>
    <year>1992</year>
    <decimal_date>1992.292</decimal_date>
    <ch4_ppb>1736.64</ch4_ppb>
    <ch4_trend_ppb>1735.02</ch4_trend_ppb>
    <uncertainty>0.59</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>1992-05</month>
    <year>1992</year>
    <decimal_date>1992.375</decimal_date>
    <ch4_ppb>1735.05</ch4_ppb>
    <ch4_trend_ppb>1735.35</ch4_trend_ppb>
    <uncertainty>0.81</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>1992-06</month>
    <year>1992</year>
    <decimal_date>1992.458</decimal_date>
    <ch4_ppb>1731.59</ch4_ppb>
    <ch4_trend_ppb>1735.55</ch4_trend_ppb>
    <uncertainty>1.03</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>1992-07</month>
    <year>1992</year>
    <decimal_date>1992.542</decimal_date>
    <ch4_ppb>1728.78</ch4_ppb>
    <ch4_trend_ppb>1735.63</ch4_trend_ppb>
    <uncertainty>1.01</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>1992-08</month>
    <year>1992</year>
    <decimal_date>1992.625</decimal_date>
    <ch4_ppb>1730.32</ch4_ppb>
    <ch4_trend_ppb>1735.61</ch4_trend_ppb>
    <uncertainty>0.91</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>1992-09</month>
    <year>1992</year>
    <decimal_date>1992.708</decimal_date>
    <ch4_ppb>1734.62</ch4_ppb>
    <ch4_trend_ppb>1735.53</ch4_trend_ppb>
    <uncertainty>0.72</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>1992-10</month>
    <year>1992</year>
    <decimal_date>1992.792</decimal_date>
    <ch4_ppb>1737.67</ch4_ppb>
    <ch4_trend_ppb>1735.41</ch4_trend_ppb>
    <uncertainty>0.9</uncertainty>
    <trend_uncertainty>0.52</trend_uncertainty>
  </row>
  <row>
    <month>1992-11</month>
    <year>1992</year>
    <decimal_date>1992.875</decimal_date>
    <ch4_ppb>1739.21</ch4_ppb>
    <ch4_trend_ppb>1735.28</ch4_trend_ppb>
    <uncertainty>1.16</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
  </row>
  <row>
    <month>1992-12</month>
    <year>1992</year>
    <decimal_date>1992.958</decimal_date>
    <ch4_ppb>1738.53</ch4_ppb>
    <ch4_trend_ppb>1735.17</ch4_trend_ppb>
    <uncertainty>0.95</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>1993-01</month>
    <year>1993</year>
    <decimal_date>1993.042</decimal_date>
    <ch4_ppb>1735.77</ch4_ppb>
    <ch4_trend_ppb>1735.1</ch4_trend_ppb>
    <uncertainty>0.84</uncertainty>
    <trend_uncertainty>0.49</trend_uncertainty>
  </row>
  <row>
    <month>1993-02</month>
    <year>1993</year>
    <decimal_date>1993.125</decimal_date>
    <ch4_ppb>1734.36</ch4_ppb>
    <ch4_trend_ppb>1735.08</ch4_trend_ppb>
    <uncertainty>0.99</uncertainty>
    <trend_uncertainty>0.49</trend_uncertainty>
  </row>
  <row>
    <month>1993-03</month>
    <year>1993</year>
    <decimal_date>1993.208</decimal_date>
    <ch4_ppb>1735.39</ch4_ppb>
    <ch4_trend_ppb>1735.14</ch4_trend_ppb>
    <uncertainty>1.02</uncertainty>
    <trend_uncertainty>0.48</trend_uncertainty>
  </row>
  <row>
    <month>1993-04</month>
    <year>1993</year>
    <decimal_date>1993.292</decimal_date>
    <ch4_ppb>1736.59</ch4_ppb>
    <ch4_trend_ppb>1735.27</ch4_trend_ppb>
    <uncertainty>0.82</uncertainty>
    <trend_uncertainty>0.48</trend_uncertainty>
  </row>
  <row>
    <month>1993-05</month>
    <year>1993</year>
    <decimal_date>1993.375</decimal_date>
    <ch4_ppb>1735</ch4_ppb>
    <ch4_trend_ppb>1735.49</ch4_trend_ppb>
    <uncertainty>0.79</uncertainty>
    <trend_uncertainty>0.49</trend_uncertainty>
  </row>
  <row>
    <month>1993-06</month>
    <year>1993</year>
    <decimal_date>1993.458</decimal_date>
    <ch4_ppb>1730.89</ch4_ppb>
    <ch4_trend_ppb>1735.78</ch4_trend_ppb>
    <uncertainty>0.86</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>1993-07</month>
    <year>1993</year>
    <decimal_date>1993.542</decimal_date>
    <ch4_ppb>1728</ch4_ppb>
    <ch4_trend_ppb>1736.14</ch4_trend_ppb>
    <uncertainty>0.89</uncertainty>
    <trend_uncertainty>0.52</trend_uncertainty>
  </row>
  <row>
    <month>1993-08</month>
    <year>1993</year>
    <decimal_date>1993.625</decimal_date>
    <ch4_ppb>1731.13</ch4_ppb>
    <ch4_trend_ppb>1736.57</ch4_trend_ppb>
    <uncertainty>0.84</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>1993-09</month>
    <year>1993</year>
    <decimal_date>1993.708</decimal_date>
    <ch4_ppb>1738.47</ch4_ppb>
    <ch4_trend_ppb>1737.05</ch4_trend_ppb>
    <uncertainty>0.87</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>1993-10</month>
    <year>1993</year>
    <decimal_date>1993.792</decimal_date>
    <ch4_ppb>1743.37</ch4_ppb>
    <ch4_trend_ppb>1737.57</ch4_trend_ppb>
    <uncertainty>0.94</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>1993-11</month>
    <year>1993</year>
    <decimal_date>1993.875</decimal_date>
    <ch4_ppb>1745.21</ch4_ppb>
    <ch4_trend_ppb>1738.11</ch4_trend_ppb>
    <uncertainty>0.8</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>1993-12</month>
    <year>1993</year>
    <decimal_date>1993.958</decimal_date>
    <ch4_ppb>1744.29</ch4_ppb>
    <ch4_trend_ppb>1738.68</ch4_trend_ppb>
    <uncertainty>0.99</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>1994-01</month>
    <year>1994</year>
    <decimal_date>1994.042</decimal_date>
    <ch4_ppb>1741.37</ch4_ppb>
    <ch4_trend_ppb>1739.27</ch4_trend_ppb>
    <uncertainty>1.02</uncertainty>
    <trend_uncertainty>0.63</trend_uncertainty>
  </row>
  <row>
    <month>1994-02</month>
    <year>1994</year>
    <decimal_date>1994.125</decimal_date>
    <ch4_ppb>1740.83</ch4_ppb>
    <ch4_trend_ppb>1739.84</ch4_trend_ppb>
    <uncertainty>1.06</uncertainty>
    <trend_uncertainty>0.63</trend_uncertainty>
  </row>
  <row>
    <month>1994-03</month>
    <year>1994</year>
    <decimal_date>1994.208</decimal_date>
    <ch4_ppb>1741.96</ch4_ppb>
    <ch4_trend_ppb>1740.42</ch4_trend_ppb>
    <uncertainty>0.94</uncertainty>
    <trend_uncertainty>0.63</trend_uncertainty>
  </row>
  <row>
    <month>1994-04</month>
    <year>1994</year>
    <decimal_date>1994.292</decimal_date>
    <ch4_ppb>1741.99</ch4_ppb>
    <ch4_trend_ppb>1741.02</ch4_trend_ppb>
    <uncertainty>0.82</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>1994-05</month>
    <year>1994</year>
    <decimal_date>1994.375</decimal_date>
    <ch4_ppb>1740.73</ch4_ppb>
    <ch4_trend_ppb>1741.63</ch4_trend_ppb>
    <uncertainty>1.05</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>1994-06</month>
    <year>1994</year>
    <decimal_date>1994.458</decimal_date>
    <ch4_ppb>1736.9</ch4_ppb>
    <ch4_trend_ppb>1742.25</ch4_trend_ppb>
    <uncertainty>1.16</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>1994-07</month>
    <year>1994</year>
    <decimal_date>1994.542</decimal_date>
    <ch4_ppb>1732.27</ch4_ppb>
    <ch4_trend_ppb>1742.87</ch4_trend_ppb>
    <uncertainty>1.14</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>1994-08</month>
    <year>1994</year>
    <decimal_date>1994.625</decimal_date>
    <ch4_ppb>1734.04</ch4_ppb>
    <ch4_trend_ppb>1743.5</ch4_trend_ppb>
    <uncertainty>1</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>1994-09</month>
    <year>1994</year>
    <decimal_date>1994.708</decimal_date>
    <ch4_ppb>1742.96</ch4_ppb>
    <ch4_trend_ppb>1744.13</ch4_trend_ppb>
    <uncertainty>0.82</uncertainty>
    <trend_uncertainty>0.52</trend_uncertainty>
  </row>
  <row>
    <month>1994-10</month>
    <year>1994</year>
    <decimal_date>1994.792</decimal_date>
    <ch4_ppb>1749.78</ch4_ppb>
    <ch4_trend_ppb>1744.75</ch4_trend_ppb>
    <uncertainty>0.75</uncertainty>
    <trend_uncertainty>0.52</trend_uncertainty>
  </row>
  <row>
    <month>1994-11</month>
    <year>1994</year>
    <decimal_date>1994.875</decimal_date>
    <ch4_ppb>1751.26</ch4_ppb>
    <ch4_trend_ppb>1745.36</ch4_trend_ppb>
    <uncertainty>0.83</uncertainty>
    <trend_uncertainty>0.52</trend_uncertainty>
  </row>
  <row>
    <month>1994-12</month>
    <year>1994</year>
    <decimal_date>1994.958</decimal_date>
    <ch4_ppb>1751.67</ch4_ppb>
    <ch4_trend_ppb>1745.95</ch4_trend_ppb>
    <uncertainty>0.97</uncertainty>
    <trend_uncertainty>0.52</trend_uncertainty>
  </row>
  <row>
    <month>1995-01</month>
    <year>1995</year>
    <decimal_date>1995.042</decimal_date>
    <ch4_ppb>1751.14</ch4_ppb>
    <ch4_trend_ppb>1746.53</ch4_trend_ppb>
    <uncertainty>1.14</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>1995-02</month>
    <year>1995</year>
    <decimal_date>1995.125</decimal_date>
    <ch4_ppb>1749.49</ch4_ppb>
    <ch4_trend_ppb>1747.04</ch4_trend_ppb>
    <uncertainty>1.09</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>1995-03</month>
    <year>1995</year>
    <decimal_date>1995.208</decimal_date>
    <ch4_ppb>1749</ch4_ppb>
    <ch4_trend_ppb>1747.52</ch4_trend_ppb>
    <uncertainty>0.69</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>1995-04</month>
    <year>1995</year>
    <decimal_date>1995.292</decimal_date>
    <ch4_ppb>1749.42</ch4_ppb>
    <ch4_trend_ppb>1747.97</ch4_trend_ppb>
    <uncertainty>0.73</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>1995-05</month>
    <year>1995</year>
    <decimal_date>1995.375</decimal_date>
    <ch4_ppb>1747.65</ch4_ppb>
    <ch4_trend_ppb>1748.37</ch4_trend_ppb>
    <uncertainty>0.97</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>1995-06</month>
    <year>1995</year>
    <decimal_date>1995.458</decimal_date>
    <ch4_ppb>1742.84</ch4_ppb>
    <ch4_trend_ppb>1748.72</ch4_trend_ppb>
    <uncertainty>0.92</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
  </row>
  <row>
    <month>1995-07</month>
    <year>1995</year>
    <decimal_date>1995.542</decimal_date>
    <ch4_ppb>1740.15</ch4_ppb>
    <ch4_trend_ppb>1749.02</ch4_trend_ppb>
    <uncertainty>0.91</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>1995-08</month>
    <year>1995</year>
    <decimal_date>1995.625</decimal_date>
    <ch4_ppb>1743.58</ch4_ppb>
    <ch4_trend_ppb>1749.28</ch4_trend_ppb>
    <uncertainty>1.17</uncertainty>
    <trend_uncertainty>0.49</trend_uncertainty>
  </row>
  <row>
    <month>1995-09</month>
    <year>1995</year>
    <decimal_date>1995.708</decimal_date>
    <ch4_ppb>1749.8</ch4_ppb>
    <ch4_trend_ppb>1749.5</ch4_trend_ppb>
    <uncertainty>1.15</uncertainty>
    <trend_uncertainty>0.48</trend_uncertainty>
  </row>
  <row>
    <month>1995-10</month>
    <year>1995</year>
    <decimal_date>1995.792</decimal_date>
    <ch4_ppb>1754.34</ch4_ppb>
    <ch4_trend_ppb>1749.69</ch4_trend_ppb>
    <uncertainty>0.91</uncertainty>
    <trend_uncertainty>0.48</trend_uncertainty>
  </row>
  <row>
    <month>1995-11</month>
    <year>1995</year>
    <decimal_date>1995.875</decimal_date>
    <ch4_ppb>1755.49</ch4_ppb>
    <ch4_trend_ppb>1749.85</ch4_trend_ppb>
    <uncertainty>0.95</uncertainty>
    <trend_uncertainty>0.49</trend_uncertainty>
  </row>
  <row>
    <month>1995-12</month>
    <year>1995</year>
    <decimal_date>1995.958</decimal_date>
    <ch4_ppb>1753.87</ch4_ppb>
    <ch4_trend_ppb>1750.01</ch4_trend_ppb>
    <uncertainty>0.86</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
  </row>
  <row>
    <month>1996-01</month>
    <year>1996</year>
    <decimal_date>1996.042</decimal_date>
    <ch4_ppb>1752.24</ch4_ppb>
    <ch4_trend_ppb>1750.17</ch4_trend_ppb>
    <uncertainty>1.03</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>1996-02</month>
    <year>1996</year>
    <decimal_date>1996.125</decimal_date>
    <ch4_ppb>1752.73</ch4_ppb>
    <ch4_trend_ppb>1750.33</ch4_trend_ppb>
    <uncertainty>1.02</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>1996-03</month>
    <year>1996</year>
    <decimal_date>1996.208</decimal_date>
    <ch4_ppb>1752.24</ch4_ppb>
    <ch4_trend_ppb>1750.49</ch4_trend_ppb>
    <uncertainty>0.83</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>1996-04</month>
    <year>1996</year>
    <decimal_date>1996.292</decimal_date>
    <ch4_ppb>1749.62</ch4_ppb>
    <ch4_trend_ppb>1750.68</ch4_trend_ppb>
    <uncertainty>1.03</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>1996-05</month>
    <year>1996</year>
    <decimal_date>1996.375</decimal_date>
    <ch4_ppb>1748.29</ch4_ppb>
    <ch4_trend_ppb>1750.87</ch4_trend_ppb>
    <uncertainty>1.1</uncertainty>
    <trend_uncertainty>0.64</trend_uncertainty>
  </row>
  <row>
    <month>1996-06</month>
    <year>1996</year>
    <decimal_date>1996.458</decimal_date>
    <ch4_ppb>1746.05</ch4_ppb>
    <ch4_trend_ppb>1751.08</ch4_trend_ppb>
    <uncertainty>0.95</uncertainty>
    <trend_uncertainty>0.66</trend_uncertainty>
  </row>
  <row>
    <month>1996-07</month>
    <year>1996</year>
    <decimal_date>1996.542</decimal_date>
    <ch4_ppb>1742.06</ch4_ppb>
    <ch4_trend_ppb>1751.3</ch4_trend_ppb>
    <uncertainty>0.88</uncertainty>
    <trend_uncertainty>0.67</trend_uncertainty>
  </row>
  <row>
    <month>1996-08</month>
    <year>1996</year>
    <decimal_date>1996.625</decimal_date>
    <ch4_ppb>1744.28</ch4_ppb>
    <ch4_trend_ppb>1751.53</ch4_trend_ppb>
    <uncertainty>1.16</uncertainty>
    <trend_uncertainty>0.67</trend_uncertainty>
  </row>
  <row>
    <month>1996-09</month>
    <year>1996</year>
    <decimal_date>1996.708</decimal_date>
    <ch4_ppb>1752.65</ch4_ppb>
    <ch4_trend_ppb>1751.76</ch4_trend_ppb>
    <uncertainty>1.22</uncertainty>
    <trend_uncertainty>0.66</trend_uncertainty>
  </row>
  <row>
    <month>1996-10</month>
    <year>1996</year>
    <decimal_date>1996.792</decimal_date>
    <ch4_ppb>1758.9</ch4_ppb>
    <ch4_trend_ppb>1751.99</ch4_trend_ppb>
    <uncertainty>0.84</uncertainty>
    <trend_uncertainty>0.63</trend_uncertainty>
  </row>
  <row>
    <month>1996-11</month>
    <year>1996</year>
    <decimal_date>1996.875</decimal_date>
    <ch4_ppb>1760.08</ch4_ppb>
    <ch4_trend_ppb>1752.22</ch4_trend_ppb>
    <uncertainty>0.87</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>1996-12</month>
    <year>1996</year>
    <decimal_date>1996.958</decimal_date>
    <ch4_ppb>1756.97</ch4_ppb>
    <ch4_trend_ppb>1752.45</ch4_trend_ppb>
    <uncertainty>0.79</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>1997-01</month>
    <year>1997</year>
    <decimal_date>1997.042</decimal_date>
    <ch4_ppb>1753.4</ch4_ppb>
    <ch4_trend_ppb>1752.69</ch4_trend_ppb>
    <uncertainty>0.86</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>1997-02</month>
    <year>1997</year>
    <decimal_date>1997.125</decimal_date>
    <ch4_ppb>1753.85</ch4_ppb>
    <ch4_trend_ppb>1752.92</ch4_trend_ppb>
    <uncertainty>1.05</uncertainty>
    <trend_uncertainty>0.49</trend_uncertainty>
  </row>
  <row>
    <month>1997-03</month>
    <year>1997</year>
    <decimal_date>1997.208</decimal_date>
    <ch4_ppb>1755.68</ch4_ppb>
    <ch4_trend_ppb>1753.18</ch4_trend_ppb>
    <uncertainty>0.78</uncertainty>
    <trend_uncertainty>0.46</trend_uncertainty>
  </row>
  <row>
    <month>1997-04</month>
    <year>1997</year>
    <decimal_date>1997.292</decimal_date>
    <ch4_ppb>1755.53</ch4_ppb>
    <ch4_trend_ppb>1753.47</ch4_trend_ppb>
    <uncertainty>0.87</uncertainty>
    <trend_uncertainty>0.42</trend_uncertainty>
  </row>
  <row>
    <month>1997-05</month>
    <year>1997</year>
    <decimal_date>1997.375</decimal_date>
    <ch4_ppb>1753.8</ch4_ppb>
    <ch4_trend_ppb>1753.81</ch4_trend_ppb>
    <uncertainty>0.7</uncertainty>
    <trend_uncertainty>0.39</trend_uncertainty>
  </row>
  <row>
    <month>1997-06</month>
    <year>1997</year>
    <decimal_date>1997.458</decimal_date>
    <ch4_ppb>1750.09</ch4_ppb>
    <ch4_trend_ppb>1754.2</ch4_trend_ppb>
    <uncertainty>0.88</uncertainty>
    <trend_uncertainty>0.37</trend_uncertainty>
  </row>
  <row>
    <month>1997-07</month>
    <year>1997</year>
    <decimal_date>1997.542</decimal_date>
    <ch4_ppb>1746.03</ch4_ppb>
    <ch4_trend_ppb>1754.67</ch4_trend_ppb>
    <uncertainty>0.93</uncertainty>
    <trend_uncertainty>0.36</trend_uncertainty>
  </row>
  <row>
    <month>1997-08</month>
    <year>1997</year>
    <decimal_date>1997.625</decimal_date>
    <ch4_ppb>1747.74</ch4_ppb>
    <ch4_trend_ppb>1755.23</ch4_trend_ppb>
    <uncertainty>0.85</uncertainty>
    <trend_uncertainty>0.38</trend_uncertainty>
  </row>
  <row>
    <month>1997-09</month>
    <year>1997</year>
    <decimal_date>1997.708</decimal_date>
    <ch4_ppb>1755</ch4_ppb>
    <ch4_trend_ppb>1755.88</ch4_trend_ppb>
    <uncertainty>1</uncertainty>
    <trend_uncertainty>0.4</trend_uncertainty>
  </row>
  <row>
    <month>1997-10</month>
    <year>1997</year>
    <decimal_date>1997.792</decimal_date>
    <ch4_ppb>1760.28</ch4_ppb>
    <ch4_trend_ppb>1756.63</ch4_trend_ppb>
    <uncertainty>0.83</uncertainty>
    <trend_uncertainty>0.43</trend_uncertainty>
  </row>
  <row>
    <month>1997-11</month>
    <year>1997</year>
    <decimal_date>1997.875</decimal_date>
    <ch4_ppb>1761.69</ch4_ppb>
    <ch4_trend_ppb>1757.47</ch4_trend_ppb>
    <uncertainty>0.95</uncertainty>
    <trend_uncertainty>0.46</trend_uncertainty>
  </row>
  <row>
    <month>1997-12</month>
    <year>1997</year>
    <decimal_date>1997.958</decimal_date>
    <ch4_ppb>1761.9</ch4_ppb>
    <ch4_trend_ppb>1758.41</ch4_trend_ppb>
    <uncertainty>0.8</uncertainty>
    <trend_uncertainty>0.49</trend_uncertainty>
  </row>
  <row>
    <month>1998-01</month>
    <year>1998</year>
    <decimal_date>1998.042</decimal_date>
    <ch4_ppb>1761.47</ch4_ppb>
    <ch4_trend_ppb>1759.45</ch4_trend_ppb>
    <uncertainty>0.82</uncertainty>
    <trend_uncertainty>0.52</trend_uncertainty>
  </row>
  <row>
    <month>1998-02</month>
    <year>1998</year>
    <decimal_date>1998.125</decimal_date>
    <ch4_ppb>1761.47</ch4_ppb>
    <ch4_trend_ppb>1760.51</ch4_trend_ppb>
    <uncertainty>1.33</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>1998-03</month>
    <year>1998</year>
    <decimal_date>1998.208</decimal_date>
    <ch4_ppb>1762.97</ch4_ppb>
    <ch4_trend_ppb>1761.62</ch4_trend_ppb>
    <uncertainty>1.53</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>1998-04</month>
    <year>1998</year>
    <decimal_date>1998.292</decimal_date>
    <ch4_ppb>1764.74</ch4_ppb>
    <ch4_trend_ppb>1762.8</ch4_trend_ppb>
    <uncertainty>1.06</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>1998-05</month>
    <year>1998</year>
    <decimal_date>1998.375</decimal_date>
    <ch4_ppb>1764.3</ch4_ppb>
    <ch4_trend_ppb>1763.99</ch4_trend_ppb>
    <uncertainty>0.89</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>1998-06</month>
    <year>1998</year>
    <decimal_date>1998.458</decimal_date>
    <ch4_ppb>1760.37</ch4_ppb>
    <ch4_trend_ppb>1765.16</ch4_trend_ppb>
    <uncertainty>0.73</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>1998-07</month>
    <year>1998</year>
    <decimal_date>1998.542</decimal_date>
    <ch4_ppb>1756.14</ch4_ppb>
    <ch4_trend_ppb>1766.29</ch4_trend_ppb>
    <uncertainty>0.91</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>1998-08</month>
    <year>1998</year>
    <decimal_date>1998.625</decimal_date>
    <ch4_ppb>1760.2</ch4_ppb>
    <ch4_trend_ppb>1767.38</ch4_trend_ppb>
    <uncertainty>0.84</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>1998-09</month>
    <year>1998</year>
    <decimal_date>1998.708</decimal_date>
    <ch4_ppb>1770.73</ch4_ppb>
    <ch4_trend_ppb>1768.37</ch4_trend_ppb>
    <uncertainty>1.16</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>1998-10</month>
    <year>1998</year>
    <decimal_date>1998.792</decimal_date>
    <ch4_ppb>1776.27</ch4_ppb>
    <ch4_trend_ppb>1769.26</ch4_trend_ppb>
    <uncertainty>1.03</uncertainty>
    <trend_uncertainty>0.63</trend_uncertainty>
  </row>
  <row>
    <month>1998-11</month>
    <year>1998</year>
    <decimal_date>1998.875</decimal_date>
    <ch4_ppb>1775.53</ch4_ppb>
    <ch4_trend_ppb>1770.05</ch4_trend_ppb>
    <uncertainty>0.75</uncertainty>
    <trend_uncertainty>0.64</trend_uncertainty>
  </row>
  <row>
    <month>1998-12</month>
    <year>1998</year>
    <decimal_date>1998.958</decimal_date>
    <ch4_ppb>1774.11</ch4_ppb>
    <ch4_trend_ppb>1770.74</ch4_trend_ppb>
    <uncertainty>0.8</uncertainty>
    <trend_uncertainty>0.65</trend_uncertainty>
  </row>
  <row>
    <month>1999-01</month>
    <year>1999</year>
    <decimal_date>1999.042</decimal_date>
    <ch4_ppb>1773.8</ch4_ppb>
    <ch4_trend_ppb>1771.33</ch4_trend_ppb>
    <uncertainty>1.03</uncertainty>
    <trend_uncertainty>0.65</trend_uncertainty>
  </row>
  <row>
    <month>1999-02</month>
    <year>1999</year>
    <decimal_date>1999.125</decimal_date>
    <ch4_ppb>1773.88</ch4_ppb>
    <ch4_trend_ppb>1771.79</ch4_trend_ppb>
    <uncertainty>1.45</uncertainty>
    <trend_uncertainty>0.64</trend_uncertainty>
  </row>
  <row>
    <month>1999-03</month>
    <year>1999</year>
    <decimal_date>1999.208</decimal_date>
    <ch4_ppb>1774.58</ch4_ppb>
    <ch4_trend_ppb>1772.16</ch4_trend_ppb>
    <uncertainty>1.17</uncertainty>
    <trend_uncertainty>0.64</trend_uncertainty>
  </row>
  <row>
    <month>1999-04</month>
    <year>1999</year>
    <decimal_date>1999.292</decimal_date>
    <ch4_ppb>1774.96</ch4_ppb>
    <ch4_trend_ppb>1772.46</ch4_trend_ppb>
    <uncertainty>0.97</uncertainty>
    <trend_uncertainty>0.63</trend_uncertainty>
  </row>
  <row>
    <month>1999-05</month>
    <year>1999</year>
    <decimal_date>1999.375</decimal_date>
    <ch4_ppb>1772.66</ch4_ppb>
    <ch4_trend_ppb>1772.69</ch4_trend_ppb>
    <uncertainty>0.91</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>1999-06</month>
    <year>1999</year>
    <decimal_date>1999.458</decimal_date>
    <ch4_ppb>1767.35</ch4_ppb>
    <ch4_trend_ppb>1772.87</ch4_trend_ppb>
    <uncertainty>0.76</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>1999-07</month>
    <year>1999</year>
    <decimal_date>1999.542</decimal_date>
    <ch4_ppb>1762.93</ch4_ppb>
    <ch4_trend_ppb>1773</ch4_trend_ppb>
    <uncertainty>0.76</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>1999-08</month>
    <year>1999</year>
    <decimal_date>1999.625</decimal_date>
    <ch4_ppb>1764.61</ch4_ppb>
    <ch4_trend_ppb>1773.1</ch4_trend_ppb>
    <uncertainty>0.87</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>1999-09</month>
    <year>1999</year>
    <decimal_date>1999.708</decimal_date>
    <ch4_ppb>1771.02</ch4_ppb>
    <ch4_trend_ppb>1773.17</ch4_trend_ppb>
    <uncertainty>0.9</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>1999-10</month>
    <year>1999</year>
    <decimal_date>1999.792</decimal_date>
    <ch4_ppb>1776.61</ch4_ppb>
    <ch4_trend_ppb>1773.22</ch4_trend_ppb>
    <uncertainty>0.85</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>1999-11</month>
    <year>1999</year>
    <decimal_date>1999.875</decimal_date>
    <ch4_ppb>1778.53</ch4_ppb>
    <ch4_trend_ppb>1773.26</ch4_trend_ppb>
    <uncertainty>0.81</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>1999-12</month>
    <year>1999</year>
    <decimal_date>1999.958</decimal_date>
    <ch4_ppb>1777.24</ch4_ppb>
    <ch4_trend_ppb>1773.29</ch4_trend_ppb>
    <uncertainty>0.84</uncertainty>
    <trend_uncertainty>0.64</trend_uncertainty>
  </row>
  <row>
    <month>2000-01</month>
    <year>2000</year>
    <decimal_date>2000.042</decimal_date>
    <ch4_ppb>1775.53</ch4_ppb>
    <ch4_trend_ppb>1773.3</ch4_trend_ppb>
    <uncertainty>1.14</uncertainty>
    <trend_uncertainty>0.67</trend_uncertainty>
  </row>
  <row>
    <month>2000-02</month>
    <year>2000</year>
    <decimal_date>2000.125</decimal_date>
    <ch4_ppb>1775.44</ch4_ppb>
    <ch4_trend_ppb>1773.3</ch4_trend_ppb>
    <uncertainty>1.45</uncertainty>
    <trend_uncertainty>0.68</trend_uncertainty>
  </row>
  <row>
    <month>2000-03</month>
    <year>2000</year>
    <decimal_date>2000.208</decimal_date>
    <ch4_ppb>1776.5</ch4_ppb>
    <ch4_trend_ppb>1773.28</ch4_trend_ppb>
    <uncertainty>1.49</uncertainty>
    <trend_uncertainty>0.69</trend_uncertainty>
  </row>
  <row>
    <month>2000-04</month>
    <year>2000</year>
    <decimal_date>2000.292</decimal_date>
    <ch4_ppb>1777.21</ch4_ppb>
    <ch4_trend_ppb>1773.24</ch4_trend_ppb>
    <uncertainty>1.24</uncertainty>
    <trend_uncertainty>0.7</trend_uncertainty>
  </row>
  <row>
    <month>2000-05</month>
    <year>2000</year>
    <decimal_date>2000.375</decimal_date>
    <ch4_ppb>1774.57</ch4_ppb>
    <ch4_trend_ppb>1773.17</ch4_trend_ppb>
    <uncertainty>1.16</uncertainty>
    <trend_uncertainty>0.71</trend_uncertainty>
  </row>
  <row>
    <month>2000-06</month>
    <year>2000</year>
    <decimal_date>2000.458</decimal_date>
    <ch4_ppb>1768.14</ch4_ppb>
    <ch4_trend_ppb>1773.08</ch4_trend_ppb>
    <uncertainty>1.06</uncertainty>
    <trend_uncertainty>0.7</trend_uncertainty>
  </row>
  <row>
    <month>2000-07</month>
    <year>2000</year>
    <decimal_date>2000.542</decimal_date>
    <ch4_ppb>1763.45</ch4_ppb>
    <ch4_trend_ppb>1772.96</ch4_trend_ppb>
    <uncertainty>0.74</uncertainty>
    <trend_uncertainty>0.7</trend_uncertainty>
  </row>
  <row>
    <month>2000-08</month>
    <year>2000</year>
    <decimal_date>2000.625</decimal_date>
    <ch4_ppb>1765.44</ch4_ppb>
    <ch4_trend_ppb>1772.81</ch4_trend_ppb>
    <uncertainty>0.98</uncertainty>
    <trend_uncertainty>0.69</trend_uncertainty>
  </row>
  <row>
    <month>2000-09</month>
    <year>2000</year>
    <decimal_date>2000.708</decimal_date>
    <ch4_ppb>1772.05</ch4_ppb>
    <ch4_trend_ppb>1772.64</ch4_trend_ppb>
    <uncertainty>1.05</uncertainty>
    <trend_uncertainty>0.68</trend_uncertainty>
  </row>
  <row>
    <month>2000-10</month>
    <year>2000</year>
    <decimal_date>2000.792</decimal_date>
    <ch4_ppb>1777.09</ch4_ppb>
    <ch4_trend_ppb>1772.45</ch4_trend_ppb>
    <uncertainty>0.92</uncertainty>
    <trend_uncertainty>0.66</trend_uncertainty>
  </row>
  <row>
    <month>2000-11</month>
    <year>2000</year>
    <decimal_date>2000.875</decimal_date>
    <ch4_ppb>1777.71</ch4_ppb>
    <ch4_trend_ppb>1772.26</ch4_trend_ppb>
    <uncertainty>0.91</uncertainty>
    <trend_uncertainty>0.65</trend_uncertainty>
  </row>
  <row>
    <month>2000-12</month>
    <year>2000</year>
    <decimal_date>2000.958</decimal_date>
    <ch4_ppb>1775.32</ch4_ppb>
    <ch4_trend_ppb>1772.06</ch4_trend_ppb>
    <uncertainty>0.95</uncertainty>
    <trend_uncertainty>0.64</trend_uncertainty>
  </row>
  <row>
    <month>2001-01</month>
    <year>2001</year>
    <decimal_date>2001.042</decimal_date>
    <ch4_ppb>1772.87</ch4_ppb>
    <ch4_trend_ppb>1771.86</ch4_trend_ppb>
    <uncertainty>0.81</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>2001-02</month>
    <year>2001</year>
    <decimal_date>2001.125</decimal_date>
    <ch4_ppb>1772.51</ch4_ppb>
    <ch4_trend_ppb>1771.68</ch4_trend_ppb>
    <uncertainty>0.91</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2001-03</month>
    <year>2001</year>
    <decimal_date>2001.208</decimal_date>
    <ch4_ppb>1773.65</ch4_ppb>
    <ch4_trend_ppb>1771.52</ch4_trend_ppb>
    <uncertainty>0.99</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>2001-04</month>
    <year>2001</year>
    <decimal_date>2001.292</decimal_date>
    <ch4_ppb>1773.86</ch4_ppb>
    <ch4_trend_ppb>1771.37</ch4_trend_ppb>
    <uncertainty>0.72</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>2001-05</month>
    <year>2001</year>
    <decimal_date>2001.375</decimal_date>
    <ch4_ppb>1770.87</ch4_ppb>
    <ch4_trend_ppb>1771.26</ch4_trend_ppb>
    <uncertainty>0.85</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>2001-06</month>
    <year>2001</year>
    <decimal_date>2001.458</decimal_date>
    <ch4_ppb>1766.1</ch4_ppb>
    <ch4_trend_ppb>1771.17</ch4_trend_ppb>
    <uncertainty>0.98</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>2001-07</month>
    <year>2001</year>
    <decimal_date>2001.542</decimal_date>
    <ch4_ppb>1762.99</ch4_ppb>
    <ch4_trend_ppb>1771.11</ch4_trend_ppb>
    <uncertainty>0.96</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>2001-08</month>
    <year>2001</year>
    <decimal_date>2001.625</decimal_date>
    <ch4_ppb>1764.49</ch4_ppb>
    <ch4_trend_ppb>1771.09</ch4_trend_ppb>
    <uncertainty>0.98</uncertainty>
    <trend_uncertainty>0.52</trend_uncertainty>
  </row>
  <row>
    <month>2001-09</month>
    <year>2001</year>
    <decimal_date>2001.708</decimal_date>
    <ch4_ppb>1770.46</ch4_ppb>
    <ch4_trend_ppb>1771.09</ch4_trend_ppb>
    <uncertainty>0.94</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>2001-10</month>
    <year>2001</year>
    <decimal_date>2001.792</decimal_date>
    <ch4_ppb>1775.49</ch4_ppb>
    <ch4_trend_ppb>1771.12</ch4_trend_ppb>
    <uncertainty>0.8</uncertainty>
    <trend_uncertainty>0.48</trend_uncertainty>
  </row>
  <row>
    <month>2001-11</month>
    <year>2001</year>
    <decimal_date>2001.875</decimal_date>
    <ch4_ppb>1776.56</ch4_ppb>
    <ch4_trend_ppb>1771.18</ch4_trend_ppb>
    <uncertainty>0.78</uncertainty>
    <trend_uncertainty>0.46</trend_uncertainty>
  </row>
  <row>
    <month>2001-12</month>
    <year>2001</year>
    <decimal_date>2001.958</decimal_date>
    <ch4_ppb>1775.94</ch4_ppb>
    <ch4_trend_ppb>1771.25</ch4_trend_ppb>
    <uncertainty>1.01</uncertainty>
    <trend_uncertainty>0.44</trend_uncertainty>
  </row>
  <row>
    <month>2002-01</month>
    <year>2002</year>
    <decimal_date>2002.042</decimal_date>
    <ch4_ppb>1774.12</ch4_ppb>
    <ch4_trend_ppb>1771.35</ch4_trend_ppb>
    <uncertainty>1.25</uncertainty>
    <trend_uncertainty>0.42</trend_uncertainty>
  </row>
  <row>
    <month>2002-02</month>
    <year>2002</year>
    <decimal_date>2002.125</decimal_date>
    <ch4_ppb>1772.85</ch4_ppb>
    <ch4_trend_ppb>1771.46</ch4_trend_ppb>
    <uncertainty>1.02</uncertainty>
    <trend_uncertainty>0.42</trend_uncertainty>
  </row>
  <row>
    <month>2002-03</month>
    <year>2002</year>
    <decimal_date>2002.208</decimal_date>
    <ch4_ppb>1773.42</ch4_ppb>
    <ch4_trend_ppb>1771.59</ch4_trend_ppb>
    <uncertainty>0.63</uncertainty>
    <trend_uncertainty>0.41</trend_uncertainty>
  </row>
  <row>
    <month>2002-04</month>
    <year>2002</year>
    <decimal_date>2002.292</decimal_date>
    <ch4_ppb>1772.73</ch4_ppb>
    <ch4_trend_ppb>1771.74</ch4_trend_ppb>
    <uncertainty>0.68</uncertainty>
    <trend_uncertainty>0.42</trend_uncertainty>
  </row>
  <row>
    <month>2002-05</month>
    <year>2002</year>
    <decimal_date>2002.375</decimal_date>
    <ch4_ppb>1770.28</ch4_ppb>
    <ch4_trend_ppb>1771.92</ch4_trend_ppb>
    <uncertainty>0.66</uncertainty>
    <trend_uncertainty>0.43</trend_uncertainty>
  </row>
  <row>
    <month>2002-06</month>
    <year>2002</year>
    <decimal_date>2002.458</decimal_date>
    <ch4_ppb>1766.9</ch4_ppb>
    <ch4_trend_ppb>1772.13</ch4_trend_ppb>
    <uncertainty>0.81</uncertainty>
    <trend_uncertainty>0.45</trend_uncertainty>
  </row>
  <row>
    <month>2002-07</month>
    <year>2002</year>
    <decimal_date>2002.542</decimal_date>
    <ch4_ppb>1764.25</ch4_ppb>
    <ch4_trend_ppb>1772.37</ch4_trend_ppb>
    <uncertainty>0.85</uncertainty>
    <trend_uncertainty>0.46</trend_uncertainty>
  </row>
  <row>
    <month>2002-08</month>
    <year>2002</year>
    <decimal_date>2002.625</decimal_date>
    <ch4_ppb>1766.97</ch4_ppb>
    <ch4_trend_ppb>1772.66</ch4_trend_ppb>
    <uncertainty>0.93</uncertainty>
    <trend_uncertainty>0.48</trend_uncertainty>
  </row>
  <row>
    <month>2002-09</month>
    <year>2002</year>
    <decimal_date>2002.708</decimal_date>
    <ch4_ppb>1773.78</ch4_ppb>
    <ch4_trend_ppb>1772.98</ch4_trend_ppb>
    <uncertainty>0.89</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>2002-10</month>
    <year>2002</year>
    <decimal_date>2002.792</decimal_date>
    <ch4_ppb>1778.26</ch4_ppb>
    <ch4_trend_ppb>1773.35</ch4_trend_ppb>
    <uncertainty>1.17</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
  </row>
  <row>
    <month>2002-11</month>
    <year>2002</year>
    <decimal_date>2002.875</decimal_date>
    <ch4_ppb>1779.48</ch4_ppb>
    <ch4_trend_ppb>1773.77</ch4_trend_ppb>
    <uncertainty>1.03</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
  </row>
  <row>
    <month>2002-12</month>
    <year>2002</year>
    <decimal_date>2002.958</decimal_date>
    <ch4_ppb>1779.66</ch4_ppb>
    <ch4_trend_ppb>1774.23</ch4_trend_ppb>
    <uncertainty>0.79</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
  </row>
  <row>
    <month>2003-01</month>
    <year>2003</year>
    <decimal_date>2003.042</decimal_date>
    <ch4_ppb>1777.54</ch4_ppb>
    <ch4_trend_ppb>1774.74</ch4_trend_ppb>
    <uncertainty>1.14</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
  </row>
  <row>
    <month>2003-02</month>
    <year>2003</year>
    <decimal_date>2003.125</decimal_date>
    <ch4_ppb>1774.81</ch4_ppb>
    <ch4_trend_ppb>1775.26</ch4_trend_ppb>
    <uncertainty>1.11</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>2003-03</month>
    <year>2003</year>
    <decimal_date>2003.208</decimal_date>
    <ch4_ppb>1774.84</ch4_ppb>
    <ch4_trend_ppb>1775.81</ch4_trend_ppb>
    <uncertainty>0.9</uncertainty>
    <trend_uncertainty>0.49</trend_uncertainty>
  </row>
  <row>
    <month>2003-04</month>
    <year>2003</year>
    <decimal_date>2003.292</decimal_date>
    <ch4_ppb>1775.8</ch4_ppb>
    <ch4_trend_ppb>1776.38</ch4_trend_ppb>
    <uncertainty>1.49</uncertainty>
    <trend_uncertainty>0.49</trend_uncertainty>
  </row>
  <row>
    <month>2003-05</month>
    <year>2003</year>
    <decimal_date>2003.375</decimal_date>
    <ch4_ppb>1774.45</ch4_ppb>
    <ch4_trend_ppb>1776.95</ch4_trend_ppb>
    <uncertainty>1.21</uncertainty>
    <trend_uncertainty>0.49</trend_uncertainty>
  </row>
  <row>
    <month>2003-06</month>
    <year>2003</year>
    <decimal_date>2003.458</decimal_date>
    <ch4_ppb>1771.7</ch4_ppb>
    <ch4_trend_ppb>1777.49</ch4_trend_ppb>
    <uncertainty>1.08</uncertainty>
    <trend_uncertainty>0.49</trend_uncertainty>
  </row>
  <row>
    <month>2003-07</month>
    <year>2003</year>
    <decimal_date>2003.542</decimal_date>
    <ch4_ppb>1770.7</ch4_ppb>
    <ch4_trend_ppb>1778</ch4_trend_ppb>
    <uncertainty>1.79</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>2003-08</month>
    <year>2003</year>
    <decimal_date>2003.625</decimal_date>
    <ch4_ppb>1774.29</ch4_ppb>
    <ch4_trend_ppb>1778.45</ch4_trend_ppb>
    <uncertainty>1.61</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>2003-09</month>
    <year>2003</year>
    <decimal_date>2003.708</decimal_date>
    <ch4_ppb>1780.57</ch4_ppb>
    <ch4_trend_ppb>1778.82</ch4_trend_ppb>
    <uncertainty>1.08</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
  </row>
  <row>
    <month>2003-10</month>
    <year>2003</year>
    <decimal_date>2003.792</decimal_date>
    <ch4_ppb>1784.68</ch4_ppb>
    <ch4_trend_ppb>1779.09</ch4_trend_ppb>
    <uncertainty>0.82</uncertainty>
    <trend_uncertainty>0.52</trend_uncertainty>
  </row>
  <row>
    <month>2003-11</month>
    <year>2003</year>
    <decimal_date>2003.875</decimal_date>
    <ch4_ppb>1785.26</ch4_ppb>
    <ch4_trend_ppb>1779.26</ch4_trend_ppb>
    <uncertainty>0.99</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>2003-12</month>
    <year>2003</year>
    <decimal_date>2003.958</decimal_date>
    <ch4_ppb>1783.57</ch4_ppb>
    <ch4_trend_ppb>1779.32</ch4_trend_ppb>
    <uncertainty>1.02</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>2004-01</month>
    <year>2004</year>
    <decimal_date>2004.042</decimal_date>
    <ch4_ppb>1780.73</ch4_ppb>
    <ch4_trend_ppb>1779.26</ch4_trend_ppb>
    <uncertainty>0.93</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>2004-02</month>
    <year>2004</year>
    <decimal_date>2004.125</decimal_date>
    <ch4_ppb>1779.67</ch4_ppb>
    <ch4_trend_ppb>1779.1</ch4_trend_ppb>
    <uncertainty>0.87</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>2004-03</month>
    <year>2004</year>
    <decimal_date>2004.208</decimal_date>
    <ch4_ppb>1780.93</ch4_ppb>
    <ch4_trend_ppb>1778.83</ch4_trend_ppb>
    <uncertainty>0.82</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>2004-04</month>
    <year>2004</year>
    <decimal_date>2004.292</decimal_date>
    <ch4_ppb>1780.87</ch4_ppb>
    <ch4_trend_ppb>1778.47</ch4_trend_ppb>
    <uncertainty>0.78</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>2004-05</month>
    <year>2004</year>
    <decimal_date>2004.375</decimal_date>
    <ch4_ppb>1777.74</ch4_ppb>
    <ch4_trend_ppb>1778.03</ch4_trend_ppb>
    <uncertainty>0.87</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>2004-06</month>
    <year>2004</year>
    <decimal_date>2004.458</decimal_date>
    <ch4_ppb>1772.45</ch4_ppb>
    <ch4_trend_ppb>1777.54</ch4_trend_ppb>
    <uncertainty>1.01</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>2004-07</month>
    <year>2004</year>
    <decimal_date>2004.542</decimal_date>
    <ch4_ppb>1768.15</ch4_ppb>
    <ch4_trend_ppb>1777.02</ch4_trend_ppb>
    <uncertainty>0.74</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>2004-08</month>
    <year>2004</year>
    <decimal_date>2004.625</decimal_date>
    <ch4_ppb>1769.97</ch4_ppb>
    <ch4_trend_ppb>1776.48</ch4_trend_ppb>
    <uncertainty>0.86</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>2004-09</month>
    <year>2004</year>
    <decimal_date>2004.708</decimal_date>
    <ch4_ppb>1775.9</ch4_ppb>
    <ch4_trend_ppb>1775.97</ch4_trend_ppb>
    <uncertainty>0.94</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>2004-10</month>
    <year>2004</year>
    <decimal_date>2004.792</decimal_date>
    <ch4_ppb>1780.07</ch4_ppb>
    <ch4_trend_ppb>1775.5</ch4_trend_ppb>
    <uncertainty>0.89</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>2004-11</month>
    <year>2004</year>
    <decimal_date>2004.875</decimal_date>
    <ch4_ppb>1780.52</ch4_ppb>
    <ch4_trend_ppb>1775.09</ch4_trend_ppb>
    <uncertainty>1.08</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>2004-12</month>
    <year>2004</year>
    <decimal_date>2004.958</decimal_date>
    <ch4_ppb>1778.18</ch4_ppb>
    <ch4_trend_ppb>1774.75</ch4_trend_ppb>
    <uncertainty>1.04</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2005-01</month>
    <year>2005</year>
    <decimal_date>2005.042</decimal_date>
    <ch4_ppb>1776.13</ch4_ppb>
    <ch4_trend_ppb>1774.48</ch4_trend_ppb>
    <uncertainty>1.25</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2005-02</month>
    <year>2005</year>
    <decimal_date>2005.125</decimal_date>
    <ch4_ppb>1775.75</ch4_ppb>
    <ch4_trend_ppb>1774.31</ch4_trend_ppb>
    <uncertainty>1.09</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2005-03</month>
    <year>2005</year>
    <decimal_date>2005.208</decimal_date>
    <ch4_ppb>1775.59</ch4_ppb>
    <ch4_trend_ppb>1774.21</ch4_trend_ppb>
    <uncertainty>1.08</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>2005-04</month>
    <year>2005</year>
    <decimal_date>2005.292</decimal_date>
    <ch4_ppb>1774.79</ch4_ppb>
    <ch4_trend_ppb>1774.19</ch4_trend_ppb>
    <uncertainty>0.85</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>2005-05</month>
    <year>2005</year>
    <decimal_date>2005.375</decimal_date>
    <ch4_ppb>1772.51</ch4_ppb>
    <ch4_trend_ppb>1774.22</ch4_trend_ppb>
    <uncertainty>0.68</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>2005-06</month>
    <year>2005</year>
    <decimal_date>2005.458</decimal_date>
    <ch4_ppb>1768.82</ch4_ppb>
    <ch4_trend_ppb>1774.3</ch4_trend_ppb>
    <uncertainty>0.87</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>2005-07</month>
    <year>2005</year>
    <decimal_date>2005.542</decimal_date>
    <ch4_ppb>1766.4</ch4_ppb>
    <ch4_trend_ppb>1774.4</ch4_trend_ppb>
    <uncertainty>0.74</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2005-08</month>
    <year>2005</year>
    <decimal_date>2005.625</decimal_date>
    <ch4_ppb>1768.16</ch4_ppb>
    <ch4_trend_ppb>1774.52</ch4_trend_ppb>
    <uncertainty>0.97</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>2005-09</month>
    <year>2005</year>
    <decimal_date>2005.708</decimal_date>
    <ch4_ppb>1773.26</ch4_ppb>
    <ch4_trend_ppb>1774.63</ch4_trend_ppb>
    <uncertainty>1.25</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>2005-10</month>
    <year>2005</year>
    <decimal_date>2005.792</decimal_date>
    <ch4_ppb>1778.58</ch4_ppb>
    <ch4_trend_ppb>1774.73</ch4_trend_ppb>
    <uncertainty>1.36</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2005-11</month>
    <year>2005</year>
    <decimal_date>2005.875</decimal_date>
    <ch4_ppb>1781.24</ch4_ppb>
    <ch4_trend_ppb>1774.79</ch4_trend_ppb>
    <uncertainty>0.93</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>2005-12</month>
    <year>2005</year>
    <decimal_date>2005.958</decimal_date>
    <ch4_ppb>1780.27</ch4_ppb>
    <ch4_trend_ppb>1774.82</ch4_trend_ppb>
    <uncertainty>1.24</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>2006-01</month>
    <year>2006</year>
    <decimal_date>2006.042</decimal_date>
    <ch4_ppb>1779.53</ch4_ppb>
    <ch4_trend_ppb>1774.82</ch4_trend_ppb>
    <uncertainty>0.91</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2006-02</month>
    <year>2006</year>
    <decimal_date>2006.125</decimal_date>
    <ch4_ppb>1779.46</ch4_ppb>
    <ch4_trend_ppb>1774.8</ch4_trend_ppb>
    <uncertainty>0.9</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>2006-03</month>
    <year>2006</year>
    <decimal_date>2006.208</decimal_date>
    <ch4_ppb>1777.4</ch4_ppb>
    <ch4_trend_ppb>1774.77</ch4_trend_ppb>
    <uncertainty>0.8</uncertainty>
    <trend_uncertainty>0.52</trend_uncertainty>
  </row>
  <row>
    <month>2006-04</month>
    <year>2006</year>
    <decimal_date>2006.292</decimal_date>
    <ch4_ppb>1776.11</ch4_ppb>
    <ch4_trend_ppb>1774.73</ch4_trend_ppb>
    <uncertainty>0.63</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>2006-05</month>
    <year>2006</year>
    <decimal_date>2006.375</decimal_date>
    <ch4_ppb>1774.91</ch4_ppb>
    <ch4_trend_ppb>1774.71</ch4_trend_ppb>
    <uncertainty>0.86</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>2006-06</month>
    <year>2006</year>
    <decimal_date>2006.458</decimal_date>
    <ch4_ppb>1769.24</ch4_ppb>
    <ch4_trend_ppb>1774.73</ch4_trend_ppb>
    <uncertainty>1.25</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>2006-07</month>
    <year>2006</year>
    <decimal_date>2006.542</decimal_date>
    <ch4_ppb>1764.15</ch4_ppb>
    <ch4_trend_ppb>1774.8</ch4_trend_ppb>
    <uncertainty>1.21</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>2006-08</month>
    <year>2006</year>
    <decimal_date>2006.625</decimal_date>
    <ch4_ppb>1767.23</ch4_ppb>
    <ch4_trend_ppb>1774.95</ch4_trend_ppb>
    <uncertainty>1.29</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
  </row>
  <row>
    <month>2006-09</month>
    <year>2006</year>
    <decimal_date>2006.708</decimal_date>
    <ch4_ppb>1774.61</ch4_ppb>
    <ch4_trend_ppb>1775.17</ch4_trend_ppb>
    <uncertainty>1.26</uncertainty>
    <trend_uncertainty>0.52</trend_uncertainty>
  </row>
  <row>
    <month>2006-10</month>
    <year>2006</year>
    <decimal_date>2006.792</decimal_date>
    <ch4_ppb>1778.24</ch4_ppb>
    <ch4_trend_ppb>1775.49</ch4_trend_ppb>
    <uncertainty>0.93</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>2006-11</month>
    <year>2006</year>
    <decimal_date>2006.875</decimal_date>
    <ch4_ppb>1779.02</ch4_ppb>
    <ch4_trend_ppb>1775.9</ch4_trend_ppb>
    <uncertainty>0.79</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>2006-12</month>
    <year>2006</year>
    <decimal_date>2006.958</decimal_date>
    <ch4_ppb>1779.93</ch4_ppb>
    <ch4_trend_ppb>1776.39</ch4_trend_ppb>
    <uncertainty>0.8</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>2007-01</month>
    <year>2007</year>
    <decimal_date>2007.042</decimal_date>
    <ch4_ppb>1779.25</ch4_ppb>
    <ch4_trend_ppb>1776.98</ch4_trend_ppb>
    <uncertainty>1.11</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2007-02</month>
    <year>2007</year>
    <decimal_date>2007.125</decimal_date>
    <ch4_ppb>1778.66</ch4_ppb>
    <ch4_trend_ppb>1777.59</ch4_trend_ppb>
    <uncertainty>1.11</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2007-03</month>
    <year>2007</year>
    <decimal_date>2007.208</decimal_date>
    <ch4_ppb>1780.27</ch4_ppb>
    <ch4_trend_ppb>1778.26</ch4_trend_ppb>
    <uncertainty>0.92</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2007-04</month>
    <year>2007</year>
    <decimal_date>2007.292</decimal_date>
    <ch4_ppb>1781.02</ch4_ppb>
    <ch4_trend_ppb>1778.98</ch4_trend_ppb>
    <uncertainty>1.09</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2007-05</month>
    <year>2007</year>
    <decimal_date>2007.375</decimal_date>
    <ch4_ppb>1779.27</ch4_ppb>
    <ch4_trend_ppb>1779.72</ch4_trend_ppb>
    <uncertainty>1.28</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2007-06</month>
    <year>2007</year>
    <decimal_date>2007.458</decimal_date>
    <ch4_ppb>1775.49</ch4_ppb>
    <ch4_trend_ppb>1780.45</ch4_trend_ppb>
    <uncertainty>0.94</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2007-07</month>
    <year>2007</year>
    <decimal_date>2007.542</decimal_date>
    <ch4_ppb>1772.64</ch4_ppb>
    <ch4_trend_ppb>1781.16</ch4_trend_ppb>
    <uncertainty>0.94</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2007-08</month>
    <year>2007</year>
    <decimal_date>2007.625</decimal_date>
    <ch4_ppb>1777.32</ch4_ppb>
    <ch4_trend_ppb>1781.86</ch4_trend_ppb>
    <uncertainty>1.29</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2007-09</month>
    <year>2007</year>
    <decimal_date>2007.708</decimal_date>
    <ch4_ppb>1785.89</ch4_ppb>
    <ch4_trend_ppb>1782.51</ch4_trend_ppb>
    <uncertainty>1.27</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2007-10</month>
    <year>2007</year>
    <decimal_date>2007.792</decimal_date>
    <ch4_ppb>1789.68</ch4_ppb>
    <ch4_trend_ppb>1783.12</ch4_trend_ppb>
    <uncertainty>0.9</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>2007-11</month>
    <year>2007</year>
    <decimal_date>2007.875</decimal_date>
    <ch4_ppb>1789.31</ch4_ppb>
    <ch4_trend_ppb>1783.7</ch4_trend_ppb>
    <uncertainty>1</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>2007-12</month>
    <year>2007</year>
    <decimal_date>2007.958</decimal_date>
    <ch4_ppb>1788.1</ch4_ppb>
    <ch4_trend_ppb>1784.24</ch4_trend_ppb>
    <uncertainty>1.17</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>2008-01</month>
    <year>2008</year>
    <decimal_date>2008.042</decimal_date>
    <ch4_ppb>1786.7</ch4_ppb>
    <ch4_trend_ppb>1784.77</ch4_trend_ppb>
    <uncertainty>1.12</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>2008-02</month>
    <year>2008</year>
    <decimal_date>2008.125</decimal_date>
    <ch4_ppb>1785.81</ch4_ppb>
    <ch4_trend_ppb>1785.26</ch4_trend_ppb>
    <uncertainty>1.18</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>2008-03</month>
    <year>2008</year>
    <decimal_date>2008.208</decimal_date>
    <ch4_ppb>1786.17</ch4_ppb>
    <ch4_trend_ppb>1785.75</ch4_trend_ppb>
    <uncertainty>1.37</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>2008-04</month>
    <year>2008</year>
    <decimal_date>2008.292</decimal_date>
    <ch4_ppb>1786.88</ch4_ppb>
    <ch4_trend_ppb>1786.26</ch4_trend_ppb>
    <uncertainty>0.95</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>2008-05</month>
    <year>2008</year>
    <decimal_date>2008.375</decimal_date>
    <ch4_ppb>1785.21</ch4_ppb>
    <ch4_trend_ppb>1786.78</ch4_trend_ppb>
    <uncertainty>0.76</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2008-06</month>
    <year>2008</year>
    <decimal_date>2008.458</decimal_date>
    <ch4_ppb>1780.47</ch4_ppb>
    <ch4_trend_ppb>1787.31</ch4_trend_ppb>
    <uncertainty>0.8</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>2008-07</month>
    <year>2008</year>
    <decimal_date>2008.542</decimal_date>
    <ch4_ppb>1777.63</ch4_ppb>
    <ch4_trend_ppb>1787.86</ch4_trend_ppb>
    <uncertainty>0.86</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>2008-08</month>
    <year>2008</year>
    <decimal_date>2008.625</decimal_date>
    <ch4_ppb>1781.05</ch4_ppb>
    <ch4_trend_ppb>1788.44</ch4_trend_ppb>
    <uncertainty>0.81</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
  </row>
  <row>
    <month>2008-09</month>
    <year>2008</year>
    <decimal_date>2008.708</decimal_date>
    <ch4_ppb>1787.68</ch4_ppb>
    <ch4_trend_ppb>1789.03</ch4_trend_ppb>
    <uncertainty>0.82</uncertainty>
    <trend_uncertainty>0.48</trend_uncertainty>
  </row>
  <row>
    <month>2008-10</month>
    <year>2008</year>
    <decimal_date>2008.792</decimal_date>
    <ch4_ppb>1793.68</ch4_ppb>
    <ch4_trend_ppb>1789.62</ch4_trend_ppb>
    <uncertainty>0.84</uncertainty>
    <trend_uncertainty>0.46</trend_uncertainty>
  </row>
  <row>
    <month>2008-11</month>
    <year>2008</year>
    <decimal_date>2008.875</decimal_date>
    <ch4_ppb>1797.3</ch4_ppb>
    <ch4_trend_ppb>1790.2</ch4_trend_ppb>
    <uncertainty>1.34</uncertainty>
    <trend_uncertainty>0.45</trend_uncertainty>
  </row>
  <row>
    <month>2008-12</month>
    <year>2008</year>
    <decimal_date>2008.958</decimal_date>
    <ch4_ppb>1796.59</ch4_ppb>
    <ch4_trend_ppb>1790.78</ch4_trend_ppb>
    <uncertainty>1.25</uncertainty>
    <trend_uncertainty>0.44</trend_uncertainty>
  </row>
  <row>
    <month>2009-01</month>
    <year>2009</year>
    <decimal_date>2009.042</decimal_date>
    <ch4_ppb>1795.05</ch4_ppb>
    <ch4_trend_ppb>1791.35</ch4_trend_ppb>
    <uncertainty>0.88</uncertainty>
    <trend_uncertainty>0.45</trend_uncertainty>
  </row>
  <row>
    <month>2009-02</month>
    <year>2009</year>
    <decimal_date>2009.125</decimal_date>
    <ch4_ppb>1795.58</ch4_ppb>
    <ch4_trend_ppb>1791.86</ch4_trend_ppb>
    <uncertainty>0.98</uncertainty>
    <trend_uncertainty>0.46</trend_uncertainty>
  </row>
  <row>
    <month>2009-03</month>
    <year>2009</year>
    <decimal_date>2009.208</decimal_date>
    <ch4_ppb>1795.94</ch4_ppb>
    <ch4_trend_ppb>1792.34</ch4_trend_ppb>
    <uncertainty>1</uncertainty>
    <trend_uncertainty>0.48</trend_uncertainty>
  </row>
  <row>
    <month>2009-04</month>
    <year>2009</year>
    <decimal_date>2009.292</decimal_date>
    <ch4_ppb>1795.55</ch4_ppb>
    <ch4_trend_ppb>1792.8</ch4_trend_ppb>
    <uncertainty>0.85</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
  </row>
  <row>
    <month>2009-05</month>
    <year>2009</year>
    <decimal_date>2009.375</decimal_date>
    <ch4_ppb>1792.42</ch4_ppb>
    <ch4_trend_ppb>1793.23</ch4_trend_ppb>
    <uncertainty>0.79</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>2009-06</month>
    <year>2009</year>
    <decimal_date>2009.458</decimal_date>
    <ch4_ppb>1786.98</ch4_ppb>
    <ch4_trend_ppb>1793.62</ch4_trend_ppb>
    <uncertainty>0.87</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>2009-07</month>
    <year>2009</year>
    <decimal_date>2009.542</decimal_date>
    <ch4_ppb>1785.04</ch4_ppb>
    <ch4_trend_ppb>1793.98</ch4_trend_ppb>
    <uncertainty>0.98</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2009-08</month>
    <year>2009</year>
    <decimal_date>2009.625</decimal_date>
    <ch4_ppb>1788.92</ch4_ppb>
    <ch4_trend_ppb>1794.33</ch4_trend_ppb>
    <uncertainty>0.85</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>2009-09</month>
    <year>2009</year>
    <decimal_date>2009.708</decimal_date>
    <ch4_ppb>1794.84</ch4_ppb>
    <ch4_trend_ppb>1794.65</ch4_trend_ppb>
    <uncertainty>1.18</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>2009-10</month>
    <year>2009</year>
    <decimal_date>2009.792</decimal_date>
    <ch4_ppb>1798</ch4_ppb>
    <ch4_trend_ppb>1794.97</ch4_trend_ppb>
    <uncertainty>1.4</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>2009-11</month>
    <year>2009</year>
    <decimal_date>2009.875</decimal_date>
    <ch4_ppb>1797.85</ch4_ppb>
    <ch4_trend_ppb>1795.29</ch4_trend_ppb>
    <uncertainty>0.72</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2009-12</month>
    <year>2009</year>
    <decimal_date>2009.958</decimal_date>
    <ch4_ppb>1796.73</ch4_ppb>
    <ch4_trend_ppb>1795.61</ch4_trend_ppb>
    <uncertainty>0.91</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>2010-01</month>
    <year>2010</year>
    <decimal_date>2010.042</decimal_date>
    <ch4_ppb>1797.31</ch4_ppb>
    <ch4_trend_ppb>1795.96</ch4_trend_ppb>
    <uncertainty>1.15</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>2010-02</month>
    <year>2010</year>
    <decimal_date>2010.125</decimal_date>
    <ch4_ppb>1798.91</ch4_ppb>
    <ch4_trend_ppb>1796.31</ch4_trend_ppb>
    <uncertainty>1.21</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>2010-03</month>
    <year>2010</year>
    <decimal_date>2010.208</decimal_date>
    <ch4_ppb>1799.47</ch4_ppb>
    <ch4_trend_ppb>1796.67</ch4_trend_ppb>
    <uncertainty>1.14</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2010-04</month>
    <year>2010</year>
    <decimal_date>2010.292</decimal_date>
    <ch4_ppb>1799.57</ch4_ppb>
    <ch4_trend_ppb>1797.07</ch4_trend_ppb>
    <uncertainty>1.06</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>2010-05</month>
    <year>2010</year>
    <decimal_date>2010.375</decimal_date>
    <ch4_ppb>1797.62</ch4_ppb>
    <ch4_trend_ppb>1797.48</ch4_trend_ppb>
    <uncertainty>1.17</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2010-06</month>
    <year>2010</year>
    <decimal_date>2010.458</decimal_date>
    <ch4_ppb>1792.42</ch4_ppb>
    <ch4_trend_ppb>1797.91</ch4_trend_ppb>
    <uncertainty>1.35</uncertainty>
    <trend_uncertainty>0.64</trend_uncertainty>
  </row>
  <row>
    <month>2010-07</month>
    <year>2010</year>
    <decimal_date>2010.542</decimal_date>
    <ch4_ppb>1789.28</ch4_ppb>
    <ch4_trend_ppb>1798.35</ch4_trend_ppb>
    <uncertainty>1.03</uncertainty>
    <trend_uncertainty>0.67</trend_uncertainty>
  </row>
  <row>
    <month>2010-08</month>
    <year>2010</year>
    <decimal_date>2010.625</decimal_date>
    <ch4_ppb>1793.98</ch4_ppb>
    <ch4_trend_ppb>1798.8</ch4_trend_ppb>
    <uncertainty>1.03</uncertainty>
    <trend_uncertainty>0.7</trend_uncertainty>
  </row>
  <row>
    <month>2010-09</month>
    <year>2010</year>
    <decimal_date>2010.708</decimal_date>
    <ch4_ppb>1801.9</ch4_ppb>
    <ch4_trend_ppb>1799.25</ch4_trend_ppb>
    <uncertainty>1.01</uncertainty>
    <trend_uncertainty>0.72</trend_uncertainty>
  </row>
  <row>
    <month>2010-10</month>
    <year>2010</year>
    <decimal_date>2010.792</decimal_date>
    <ch4_ppb>1806.66</ch4_ppb>
    <ch4_trend_ppb>1799.7</ch4_trend_ppb>
    <uncertainty>1.11</uncertainty>
    <trend_uncertainty>0.72</trend_uncertainty>
  </row>
  <row>
    <month>2010-11</month>
    <year>2010</year>
    <decimal_date>2010.875</decimal_date>
    <ch4_ppb>1807</ch4_ppb>
    <ch4_trend_ppb>1800.15</ch4_trend_ppb>
    <uncertainty>1.17</uncertainty>
    <trend_uncertainty>0.72</trend_uncertainty>
  </row>
  <row>
    <month>2010-12</month>
    <year>2010</year>
    <decimal_date>2010.958</decimal_date>
    <ch4_ppb>1803.28</ch4_ppb>
    <ch4_trend_ppb>1800.6</ch4_trend_ppb>
    <uncertainty>1.09</uncertainty>
    <trend_uncertainty>0.71</trend_uncertainty>
  </row>
  <row>
    <month>2011-01</month>
    <year>2011</year>
    <decimal_date>2011.042</decimal_date>
    <ch4_ppb>1799.97</ch4_ppb>
    <ch4_trend_ppb>1801.04</ch4_trend_ppb>
    <uncertainty>1.08</uncertainty>
    <trend_uncertainty>0.69</trend_uncertainty>
  </row>
  <row>
    <month>2011-02</month>
    <year>2011</year>
    <decimal_date>2011.125</decimal_date>
    <ch4_ppb>1799.89</ch4_ppb>
    <ch4_trend_ppb>1801.45</ch4_trend_ppb>
    <uncertainty>0.93</uncertainty>
    <trend_uncertainty>0.67</trend_uncertainty>
  </row>
  <row>
    <month>2011-03</month>
    <year>2011</year>
    <decimal_date>2011.208</decimal_date>
    <ch4_ppb>1800.91</ch4_ppb>
    <ch4_trend_ppb>1801.86</ch4_trend_ppb>
    <uncertainty>0.69</uncertainty>
    <trend_uncertainty>0.65</trend_uncertainty>
  </row>
  <row>
    <month>2011-04</month>
    <year>2011</year>
    <decimal_date>2011.292</decimal_date>
    <ch4_ppb>1802.88</ch4_ppb>
    <ch4_trend_ppb>1802.28</ch4_trend_ppb>
    <uncertainty>0.85</uncertainty>
    <trend_uncertainty>0.63</trend_uncertainty>
  </row>
  <row>
    <month>2011-05</month>
    <year>2011</year>
    <decimal_date>2011.375</decimal_date>
    <ch4_ppb>1803.27</ch4_ppb>
    <ch4_trend_ppb>1802.69</ch4_trend_ppb>
    <uncertainty>0.97</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2011-06</month>
    <year>2011</year>
    <decimal_date>2011.458</decimal_date>
    <ch4_ppb>1799.03</ch4_ppb>
    <ch4_trend_ppb>1803.1</ch4_trend_ppb>
    <uncertainty>0.75</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>2011-07</month>
    <year>2011</year>
    <decimal_date>2011.542</decimal_date>
    <ch4_ppb>1796.07</ch4_ppb>
    <ch4_trend_ppb>1803.51</ch4_trend_ppb>
    <uncertainty>0.81</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>2011-08</month>
    <year>2011</year>
    <decimal_date>2011.625</decimal_date>
    <ch4_ppb>1799.03</ch4_ppb>
    <ch4_trend_ppb>1803.93</ch4_trend_ppb>
    <uncertainty>0.94</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>2011-09</month>
    <year>2011</year>
    <decimal_date>2011.708</decimal_date>
    <ch4_ppb>1804.04</ch4_ppb>
    <ch4_trend_ppb>1804.35</ch4_trend_ppb>
    <uncertainty>1.55</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>2011-10</month>
    <year>2011</year>
    <decimal_date>2011.792</decimal_date>
    <ch4_ppb>1809.48</ch4_ppb>
    <ch4_trend_ppb>1804.76</ch4_trend_ppb>
    <uncertainty>1.47</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2011-11</month>
    <year>2011</year>
    <decimal_date>2011.875</decimal_date>
    <ch4_ppb>1812.41</ch4_ppb>
    <ch4_trend_ppb>1805.19</ch4_trend_ppb>
    <uncertainty>1.24</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2011-12</month>
    <year>2011</year>
    <decimal_date>2011.958</decimal_date>
    <ch4_ppb>1810.13</ch4_ppb>
    <ch4_trend_ppb>1805.62</ch4_trend_ppb>
    <uncertainty>1.12</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2012-01</month>
    <year>2012</year>
    <decimal_date>2012.042</decimal_date>
    <ch4_ppb>1807.29</ch4_ppb>
    <ch4_trend_ppb>1806.06</ch4_trend_ppb>
    <uncertainty>1.04</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2012-02</month>
    <year>2012</year>
    <decimal_date>2012.125</decimal_date>
    <ch4_ppb>1808.18</ch4_ppb>
    <ch4_trend_ppb>1806.49</ch4_trend_ppb>
    <uncertainty>1.2</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2012-03</month>
    <year>2012</year>
    <decimal_date>2012.208</decimal_date>
    <ch4_ppb>1809.96</ch4_ppb>
    <ch4_trend_ppb>1806.93</ch4_trend_ppb>
    <uncertainty>0.76</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2012-04</month>
    <year>2012</year>
    <decimal_date>2012.292</decimal_date>
    <ch4_ppb>1808.48</ch4_ppb>
    <ch4_trend_ppb>1807.38</ch4_trend_ppb>
    <uncertainty>0.6</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2012-05</month>
    <year>2012</year>
    <decimal_date>2012.375</decimal_date>
    <ch4_ppb>1804.8</ch4_ppb>
    <ch4_trend_ppb>1807.83</ch4_trend_ppb>
    <uncertainty>1.29</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2012-06</month>
    <year>2012</year>
    <decimal_date>2012.458</decimal_date>
    <ch4_ppb>1801.01</ch4_ppb>
    <ch4_trend_ppb>1808.27</ch4_trend_ppb>
    <uncertainty>1.25</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2012-07</month>
    <year>2012</year>
    <decimal_date>2012.542</decimal_date>
    <ch4_ppb>1799.33</ch4_ppb>
    <ch4_trend_ppb>1808.71</ch4_trend_ppb>
    <uncertainty>0.99</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2012-08</month>
    <year>2012</year>
    <decimal_date>2012.625</decimal_date>
    <ch4_ppb>1803.24</ch4_ppb>
    <ch4_trend_ppb>1809.14</ch4_trend_ppb>
    <uncertainty>0.88</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>2012-09</month>
    <year>2012</year>
    <decimal_date>2012.708</decimal_date>
    <ch4_ppb>1810.14</ch4_ppb>
    <ch4_trend_ppb>1809.55</ch4_trend_ppb>
    <uncertainty>1.18</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>2012-10</month>
    <year>2012</year>
    <decimal_date>2012.792</decimal_date>
    <ch4_ppb>1814.83</ch4_ppb>
    <ch4_trend_ppb>1809.95</ch4_trend_ppb>
    <uncertainty>1.25</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>2012-11</month>
    <year>2012</year>
    <decimal_date>2012.875</decimal_date>
    <ch4_ppb>1815.92</ch4_ppb>
    <ch4_trend_ppb>1810.33</ch4_trend_ppb>
    <uncertainty>1.35</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>2012-12</month>
    <year>2012</year>
    <decimal_date>2012.958</decimal_date>
    <ch4_ppb>1814.57</ch4_ppb>
    <ch4_trend_ppb>1810.68</ch4_trend_ppb>
    <uncertainty>0.85</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>2013-01</month>
    <year>2013</year>
    <decimal_date>2013.042</decimal_date>
    <ch4_ppb>1814.06</ch4_ppb>
    <ch4_trend_ppb>1811.03</ch4_trend_ppb>
    <uncertainty>0.87</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>2013-02</month>
    <year>2013</year>
    <decimal_date>2013.125</decimal_date>
    <ch4_ppb>1814.15</ch4_ppb>
    <ch4_trend_ppb>1811.35</ch4_trend_ppb>
    <uncertainty>1.5</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>2013-03</month>
    <year>2013</year>
    <decimal_date>2013.208</decimal_date>
    <ch4_ppb>1813.27</ch4_ppb>
    <ch4_trend_ppb>1811.67</ch4_trend_ppb>
    <uncertainty>1.23</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>2013-04</month>
    <year>2013</year>
    <decimal_date>2013.292</decimal_date>
    <ch4_ppb>1812.83</ch4_ppb>
    <ch4_trend_ppb>1812</ch4_trend_ppb>
    <uncertainty>0.77</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>2013-05</month>
    <year>2013</year>
    <decimal_date>2013.375</decimal_date>
    <ch4_ppb>1811.94</ch4_ppb>
    <ch4_trend_ppb>1812.34</ch4_trend_ppb>
    <uncertainty>0.96</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>2013-06</month>
    <year>2013</year>
    <decimal_date>2013.458</decimal_date>
    <ch4_ppb>1808.6</ch4_ppb>
    <ch4_trend_ppb>1812.7</ch4_trend_ppb>
    <uncertainty>1.19</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>2013-07</month>
    <year>2013</year>
    <decimal_date>2013.542</decimal_date>
    <ch4_ppb>1805.96</ch4_ppb>
    <ch4_trend_ppb>1813.11</ch4_trend_ppb>
    <uncertainty>1.36</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
  </row>
  <row>
    <month>2013-08</month>
    <year>2013</year>
    <decimal_date>2013.625</decimal_date>
    <ch4_ppb>1808.52</ch4_ppb>
    <ch4_trend_ppb>1813.58</ch4_trend_ppb>
    <uncertainty>0.96</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>2013-09</month>
    <year>2013</year>
    <decimal_date>2013.708</decimal_date>
    <ch4_ppb>1814.26</ch4_ppb>
    <ch4_trend_ppb>1814.1</ch4_trend_ppb>
    <uncertainty>0.86</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2013-10</month>
    <year>2013</year>
    <decimal_date>2013.792</decimal_date>
    <ch4_ppb>1818.5</ch4_ppb>
    <ch4_trend_ppb>1814.69</ch4_trend_ppb>
    <uncertainty>0.61</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>2013-11</month>
    <year>2013</year>
    <decimal_date>2013.875</decimal_date>
    <ch4_ppb>1820.32</ch4_ppb>
    <ch4_trend_ppb>1815.36</ch4_trend_ppb>
    <uncertainty>0.83</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>2013-12</month>
    <year>2013</year>
    <decimal_date>2013.958</decimal_date>
    <ch4_ppb>1819.33</ch4_ppb>
    <ch4_trend_ppb>1816.12</ch4_trend_ppb>
    <uncertainty>0.96</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>2014-01</month>
    <year>2014</year>
    <decimal_date>2014.042</decimal_date>
    <ch4_ppb>1816.77</ch4_ppb>
    <ch4_trend_ppb>1816.97</ch4_trend_ppb>
    <uncertainty>0.96</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>2014-02</month>
    <year>2014</year>
    <decimal_date>2014.125</decimal_date>
    <ch4_ppb>1816.28</ch4_ppb>
    <ch4_trend_ppb>1817.86</ch4_trend_ppb>
    <uncertainty>1.27</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2014-03</month>
    <year>2014</year>
    <decimal_date>2014.208</decimal_date>
    <ch4_ppb>1818.07</ch4_ppb>
    <ch4_trend_ppb>1818.82</ch4_trend_ppb>
    <uncertainty>1.39</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2014-04</month>
    <year>2014</year>
    <decimal_date>2014.292</decimal_date>
    <ch4_ppb>1820.86</ch4_ppb>
    <ch4_trend_ppb>1819.86</ch4_trend_ppb>
    <uncertainty>0.82</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>2014-05</month>
    <year>2014</year>
    <decimal_date>2014.375</decimal_date>
    <ch4_ppb>1821.95</ch4_ppb>
    <ch4_trend_ppb>1820.96</ch4_trend_ppb>
    <uncertainty>0.93</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>2014-06</month>
    <year>2014</year>
    <decimal_date>2014.458</decimal_date>
    <ch4_ppb>1818.49</ch4_ppb>
    <ch4_trend_ppb>1822.09</ch4_trend_ppb>
    <uncertainty>0.85</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>2014-07</month>
    <year>2014</year>
    <decimal_date>2014.542</decimal_date>
    <ch4_ppb>1815.77</ch4_ppb>
    <ch4_trend_ppb>1823.23</ch4_trend_ppb>
    <uncertainty>0.95</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2014-08</month>
    <year>2014</year>
    <decimal_date>2014.625</decimal_date>
    <ch4_ppb>1819.9</ch4_ppb>
    <ch4_trend_ppb>1824.4</ch4_trend_ppb>
    <uncertainty>1.06</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2014-09</month>
    <year>2014</year>
    <decimal_date>2014.708</decimal_date>
    <ch4_ppb>1826.91</ch4_ppb>
    <ch4_trend_ppb>1825.53</ch4_trend_ppb>
    <uncertainty>1.06</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>2014-10</month>
    <year>2014</year>
    <decimal_date>2014.792</decimal_date>
    <ch4_ppb>1831.22</ch4_ppb>
    <ch4_trend_ppb>1826.64</ch4_trend_ppb>
    <uncertainty>0.58</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>2014-11</month>
    <year>2014</year>
    <decimal_date>2014.875</decimal_date>
    <ch4_ppb>1832.97</ch4_ppb>
    <ch4_trend_ppb>1827.72</ch4_trend_ppb>
    <uncertainty>0.66</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>2014-12</month>
    <year>2014</year>
    <decimal_date>2014.958</decimal_date>
    <ch4_ppb>1833.47</ch4_ppb>
    <ch4_trend_ppb>1828.76</ch4_trend_ppb>
    <uncertainty>1.06</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>2015-01</month>
    <year>2015</year>
    <decimal_date>2015.042</decimal_date>
    <ch4_ppb>1833.11</ch4_ppb>
    <ch4_trend_ppb>1829.77</ch4_trend_ppb>
    <uncertainty>1.09</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>2015-02</month>
    <year>2015</year>
    <decimal_date>2015.125</decimal_date>
    <ch4_ppb>1832.95</ch4_ppb>
    <ch4_trend_ppb>1830.69</ch4_trend_ppb>
    <uncertainty>0.97</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>2015-03</month>
    <year>2015</year>
    <decimal_date>2015.208</decimal_date>
    <ch4_ppb>1833.2</ch4_ppb>
    <ch4_trend_ppb>1831.58</ch4_trend_ppb>
    <uncertainty>0.8</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2015-04</month>
    <year>2015</year>
    <decimal_date>2015.292</decimal_date>
    <ch4_ppb>1833.15</ch4_ppb>
    <ch4_trend_ppb>1832.46</ch4_trend_ppb>
    <uncertainty>1.15</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>2015-05</month>
    <year>2015</year>
    <decimal_date>2015.375</decimal_date>
    <ch4_ppb>1831.52</ch4_ppb>
    <ch4_trend_ppb>1833.31</ch4_trend_ppb>
    <uncertainty>1.12</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>2015-06</month>
    <year>2015</year>
    <decimal_date>2015.458</decimal_date>
    <ch4_ppb>1827.13</ch4_ppb>
    <ch4_trend_ppb>1834.14</ch4_trend_ppb>
    <uncertainty>0.87</uncertainty>
    <trend_uncertainty>0.52</trend_uncertainty>
  </row>
  <row>
    <month>2015-07</month>
    <year>2015</year>
    <decimal_date>2015.542</decimal_date>
    <ch4_ppb>1824.57</ch4_ppb>
    <ch4_trend_ppb>1834.96</ch4_trend_ppb>
    <uncertainty>0.9</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
  </row>
  <row>
    <month>2015-08</month>
    <year>2015</year>
    <decimal_date>2015.625</decimal_date>
    <ch4_ppb>1828.96</ch4_ppb>
    <ch4_trend_ppb>1835.77</ch4_trend_ppb>
    <uncertainty>0.89</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
  </row>
  <row>
    <month>2015-09</month>
    <year>2015</year>
    <decimal_date>2015.708</decimal_date>
    <ch4_ppb>1836.23</ch4_ppb>
    <ch4_trend_ppb>1836.56</ch4_trend_ppb>
    <uncertainty>0.96</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
  </row>
  <row>
    <month>2015-10</month>
    <year>2015</year>
    <decimal_date>2015.792</decimal_date>
    <ch4_ppb>1841.48</ch4_ppb>
    <ch4_trend_ppb>1837.35</ch4_trend_ppb>
    <uncertainty>0.82</uncertainty>
    <trend_uncertainty>0.52</trend_uncertainty>
  </row>
  <row>
    <month>2015-11</month>
    <year>2015</year>
    <decimal_date>2015.875</decimal_date>
    <ch4_ppb>1844.52</ch4_ppb>
    <ch4_trend_ppb>1838.12</ch4_trend_ppb>
    <uncertainty>1.04</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
  </row>
  <row>
    <month>2015-12</month>
    <year>2015</year>
    <decimal_date>2015.958</decimal_date>
    <ch4_ppb>1844.76</ch4_ppb>
    <ch4_trend_ppb>1838.88</ch4_trend_ppb>
    <uncertainty>1.21</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>2016-01</month>
    <year>2016</year>
    <decimal_date>2016.042</decimal_date>
    <ch4_ppb>1842.53</ch4_ppb>
    <ch4_trend_ppb>1839.64</ch4_trend_ppb>
    <uncertainty>0.97</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>2016-02</month>
    <year>2016</year>
    <decimal_date>2016.125</decimal_date>
    <ch4_ppb>1841.73</ch4_ppb>
    <ch4_trend_ppb>1840.36</ch4_trend_ppb>
    <uncertainty>1.14</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>2016-03</month>
    <year>2016</year>
    <decimal_date>2016.208</decimal_date>
    <ch4_ppb>1843.05</ch4_ppb>
    <ch4_trend_ppb>1841.05</ch4_trend_ppb>
    <uncertainty>0.89</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2016-04</month>
    <year>2016</year>
    <decimal_date>2016.292</decimal_date>
    <ch4_ppb>1843.74</ch4_ppb>
    <ch4_trend_ppb>1841.73</ch4_trend_ppb>
    <uncertainty>0.7</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>2016-05</month>
    <year>2016</year>
    <decimal_date>2016.375</decimal_date>
    <ch4_ppb>1842.15</ch4_ppb>
    <ch4_trend_ppb>1842.38</ch4_trend_ppb>
    <uncertainty>0.86</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>2016-06</month>
    <year>2016</year>
    <decimal_date>2016.458</decimal_date>
    <ch4_ppb>1837.91</ch4_ppb>
    <ch4_trend_ppb>1843</ch4_trend_ppb>
    <uncertainty>1.08</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>2016-07</month>
    <year>2016</year>
    <decimal_date>2016.542</decimal_date>
    <ch4_ppb>1834.25</ch4_ppb>
    <ch4_trend_ppb>1843.59</ch4_trend_ppb>
    <uncertainty>0.97</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2016-08</month>
    <year>2016</year>
    <decimal_date>2016.625</decimal_date>
    <ch4_ppb>1836.83</ch4_ppb>
    <ch4_trend_ppb>1844.15</ch4_trend_ppb>
    <uncertainty>1.03</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>2016-09</month>
    <year>2016</year>
    <decimal_date>2016.708</decimal_date>
    <ch4_ppb>1844.35</ch4_ppb>
    <ch4_trend_ppb>1844.68</ch4_trend_ppb>
    <uncertainty>1.21</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>2016-10</month>
    <year>2016</year>
    <decimal_date>2016.792</decimal_date>
    <ch4_ppb>1849.95</ch4_ppb>
    <ch4_trend_ppb>1845.19</ch4_trend_ppb>
    <uncertainty>1.05</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>2016-11</month>
    <year>2016</year>
    <decimal_date>2016.875</decimal_date>
    <ch4_ppb>1851.45</ch4_ppb>
    <ch4_trend_ppb>1845.68</ch4_trend_ppb>
    <uncertainty>1.29</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>2016-12</month>
    <year>2016</year>
    <decimal_date>2016.958</decimal_date>
    <ch4_ppb>1851.08</ch4_ppb>
    <ch4_trend_ppb>1846.16</ch4_trend_ppb>
    <uncertainty>1.09</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>2017-01</month>
    <year>2017</year>
    <decimal_date>2017.042</decimal_date>
    <ch4_ppb>1849.78</ch4_ppb>
    <ch4_trend_ppb>1846.64</ch4_trend_ppb>
    <uncertainty>0.93</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>2017-02</month>
    <year>2017</year>
    <decimal_date>2017.125</decimal_date>
    <ch4_ppb>1848.54</ch4_ppb>
    <ch4_trend_ppb>1847.1</ch4_trend_ppb>
    <uncertainty>1.21</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>2017-03</month>
    <year>2017</year>
    <decimal_date>2017.208</decimal_date>
    <ch4_ppb>1848.29</ch4_ppb>
    <ch4_trend_ppb>1847.57</ch4_trend_ppb>
    <uncertainty>1.31</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2017-04</month>
    <year>2017</year>
    <decimal_date>2017.292</decimal_date>
    <ch4_ppb>1848.58</ch4_ppb>
    <ch4_trend_ppb>1848.07</ch4_trend_ppb>
    <uncertainty>1.3</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>2017-05</month>
    <year>2017</year>
    <decimal_date>2017.375</decimal_date>
    <ch4_ppb>1847.22</ch4_ppb>
    <ch4_trend_ppb>1848.59</ch4_trend_ppb>
    <uncertainty>1.04</uncertainty>
    <trend_uncertainty>0.64</trend_uncertainty>
  </row>
  <row>
    <month>2017-06</month>
    <year>2017</year>
    <decimal_date>2017.458</decimal_date>
    <ch4_ppb>1842.91</ch4_ppb>
    <ch4_trend_ppb>1849.12</ch4_trend_ppb>
    <uncertainty>0.94</uncertainty>
    <trend_uncertainty>0.66</trend_uncertainty>
  </row>
  <row>
    <month>2017-07</month>
    <year>2017</year>
    <decimal_date>2017.542</decimal_date>
    <ch4_ppb>1840.21</ch4_ppb>
    <ch4_trend_ppb>1849.69</ch4_trend_ppb>
    <uncertainty>1.37</uncertainty>
    <trend_uncertainty>0.67</trend_uncertainty>
  </row>
  <row>
    <month>2017-08</month>
    <year>2017</year>
    <decimal_date>2017.625</decimal_date>
    <ch4_ppb>1844.57</ch4_ppb>
    <ch4_trend_ppb>1850.28</ch4_trend_ppb>
    <uncertainty>1.35</uncertainty>
    <trend_uncertainty>0.68</trend_uncertainty>
  </row>
  <row>
    <month>2017-09</month>
    <year>2017</year>
    <decimal_date>2017.708</decimal_date>
    <ch4_ppb>1852.78</ch4_ppb>
    <ch4_trend_ppb>1850.89</ch4_trend_ppb>
    <uncertainty>1.06</uncertainty>
    <trend_uncertainty>0.69</trend_uncertainty>
  </row>
  <row>
    <month>2017-10</month>
    <year>2017</year>
    <decimal_date>2017.792</decimal_date>
    <ch4_ppb>1858.02</ch4_ppb>
    <ch4_trend_ppb>1851.53</ch4_trend_ppb>
    <uncertainty>1.01</uncertainty>
    <trend_uncertainty>0.7</trend_uncertainty>
  </row>
  <row>
    <month>2017-11</month>
    <year>2017</year>
    <decimal_date>2017.875</decimal_date>
    <ch4_ppb>1858.59</ch4_ppb>
    <ch4_trend_ppb>1852.19</ch4_trend_ppb>
    <uncertainty>0.98</uncertainty>
    <trend_uncertainty>0.71</trend_uncertainty>
  </row>
  <row>
    <month>2017-12</month>
    <year>2017</year>
    <decimal_date>2017.958</decimal_date>
    <ch4_ppb>1856.61</ch4_ppb>
    <ch4_trend_ppb>1852.87</ch4_trend_ppb>
    <uncertainty>1.08</uncertainty>
    <trend_uncertainty>0.71</trend_uncertainty>
  </row>
  <row>
    <month>2018-01</month>
    <year>2018</year>
    <decimal_date>2018.042</decimal_date>
    <ch4_ppb>1854.53</ch4_ppb>
    <ch4_trend_ppb>1853.58</ch4_trend_ppb>
    <uncertainty>1.05</uncertainty>
    <trend_uncertainty>0.72</trend_uncertainty>
  </row>
  <row>
    <month>2018-02</month>
    <year>2018</year>
    <decimal_date>2018.125</decimal_date>
    <ch4_ppb>1855.08</ch4_ppb>
    <ch4_trend_ppb>1854.28</ch4_trend_ppb>
    <uncertainty>0.94</uncertainty>
    <trend_uncertainty>0.73</trend_uncertainty>
  </row>
  <row>
    <month>2018-03</month>
    <year>2018</year>
    <decimal_date>2018.208</decimal_date>
    <ch4_ppb>1856.97</ch4_ppb>
    <ch4_trend_ppb>1854.98</ch4_trend_ppb>
    <uncertainty>1.08</uncertainty>
    <trend_uncertainty>0.74</trend_uncertainty>
  </row>
  <row>
    <month>2018-04</month>
    <year>2018</year>
    <decimal_date>2018.292</decimal_date>
    <ch4_ppb>1856.74</ch4_ppb>
    <ch4_trend_ppb>1855.72</ch4_trend_ppb>
    <uncertainty>1.05</uncertainty>
    <trend_uncertainty>0.74</trend_uncertainty>
  </row>
  <row>
    <month>2018-05</month>
    <year>2018</year>
    <decimal_date>2018.375</decimal_date>
    <ch4_ppb>1854.72</ch4_ppb>
    <ch4_trend_ppb>1856.46</ch4_trend_ppb>
    <uncertainty>1.5</uncertainty>
    <trend_uncertainty>0.75</trend_uncertainty>
  </row>
  <row>
    <month>2018-06</month>
    <year>2018</year>
    <decimal_date>2018.458</decimal_date>
    <ch4_ppb>1851.86</ch4_ppb>
    <ch4_trend_ppb>1857.2</ch4_trend_ppb>
    <uncertainty>1.54</uncertainty>
    <trend_uncertainty>0.75</trend_uncertainty>
  </row>
  <row>
    <month>2018-07</month>
    <year>2018</year>
    <decimal_date>2018.542</decimal_date>
    <ch4_ppb>1849.04</ch4_ppb>
    <ch4_trend_ppb>1857.95</ch4_trend_ppb>
    <uncertainty>1.45</uncertainty>
    <trend_uncertainty>0.75</trend_uncertainty>
  </row>
  <row>
    <month>2018-08</month>
    <year>2018</year>
    <decimal_date>2018.625</decimal_date>
    <ch4_ppb>1851.94</ch4_ppb>
    <ch4_trend_ppb>1858.7</ch4_trend_ppb>
    <uncertainty>1.55</uncertainty>
    <trend_uncertainty>0.75</trend_uncertainty>
  </row>
  <row>
    <month>2018-09</month>
    <year>2018</year>
    <decimal_date>2018.708</decimal_date>
    <ch4_ppb>1860.49</ch4_ppb>
    <ch4_trend_ppb>1859.43</ch4_trend_ppb>
    <uncertainty>0.87</uncertainty>
    <trend_uncertainty>0.74</trend_uncertainty>
  </row>
  <row>
    <month>2018-10</month>
    <year>2018</year>
    <decimal_date>2018.792</decimal_date>
    <ch4_ppb>1865.73</ch4_ppb>
    <ch4_trend_ppb>1860.16</ch4_trend_ppb>
    <uncertainty>1.1</uncertainty>
    <trend_uncertainty>0.73</trend_uncertainty>
  </row>
  <row>
    <month>2018-11</month>
    <year>2018</year>
    <decimal_date>2018.875</decimal_date>
    <ch4_ppb>1866.23</ch4_ppb>
    <ch4_trend_ppb>1860.89</ch4_trend_ppb>
    <uncertainty>1.1</uncertainty>
    <trend_uncertainty>0.71</trend_uncertainty>
  </row>
  <row>
    <month>2018-12</month>
    <year>2018</year>
    <decimal_date>2018.958</decimal_date>
    <ch4_ppb>1866.05</ch4_ppb>
    <ch4_trend_ppb>1861.6</ch4_trend_ppb>
    <uncertainty>1.03</uncertainty>
    <trend_uncertainty>0.7</trend_uncertainty>
  </row>
  <row>
    <month>2019-01</month>
    <year>2019</year>
    <decimal_date>2019.042</decimal_date>
    <ch4_ppb>1865.05</ch4_ppb>
    <ch4_trend_ppb>1862.32</ch4_trend_ppb>
    <uncertainty>1.26</uncertainty>
    <trend_uncertainty>0.67</trend_uncertainty>
  </row>
  <row>
    <month>2019-02</month>
    <year>2019</year>
    <decimal_date>2019.125</decimal_date>
    <ch4_ppb>1865.06</ch4_ppb>
    <ch4_trend_ppb>1863.01</ch4_trend_ppb>
    <uncertainty>0.82</uncertainty>
    <trend_uncertainty>0.65</trend_uncertainty>
  </row>
  <row>
    <month>2019-03</month>
    <year>2019</year>
    <decimal_date>2019.208</decimal_date>
    <ch4_ppb>1866.34</ch4_ppb>
    <ch4_trend_ppb>1863.7</ch4_trend_ppb>
    <uncertainty>0.83</uncertainty>
    <trend_uncertainty>0.63</trend_uncertainty>
  </row>
  <row>
    <month>2019-04</month>
    <year>2019</year>
    <decimal_date>2019.292</decimal_date>
    <ch4_ppb>1865.35</ch4_ppb>
    <ch4_trend_ppb>1864.42</ch4_trend_ppb>
    <uncertainty>0.6</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2019-05</month>
    <year>2019</year>
    <decimal_date>2019.375</decimal_date>
    <ch4_ppb>1861.98</ch4_ppb>
    <ch4_trend_ppb>1865.15</ch4_trend_ppb>
    <uncertainty>1.18</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>2019-06</month>
    <year>2019</year>
    <decimal_date>2019.458</decimal_date>
    <ch4_ppb>1858.64</ch4_ppb>
    <ch4_trend_ppb>1865.9</ch4_trend_ppb>
    <uncertainty>1.3</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>2019-07</month>
    <year>2019</year>
    <decimal_date>2019.542</decimal_date>
    <ch4_ppb>1858.11</ch4_ppb>
    <ch4_trend_ppb>1866.68</ch4_trend_ppb>
    <uncertainty>1.24</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2019-08</month>
    <year>2019</year>
    <decimal_date>2019.625</decimal_date>
    <ch4_ppb>1863.01</ch4_ppb>
    <ch4_trend_ppb>1867.5</ch4_trend_ppb>
    <uncertainty>1.3</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>2019-09</month>
    <year>2019</year>
    <decimal_date>2019.708</decimal_date>
    <ch4_ppb>1870.95</ch4_ppb>
    <ch4_trend_ppb>1868.34</ch4_trend_ppb>
    <uncertainty>1.18</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
  </row>
  <row>
    <month>2019-10</month>
    <year>2019</year>
    <decimal_date>2019.792</decimal_date>
    <ch4_ppb>1875.53</ch4_ppb>
    <ch4_trend_ppb>1869.22</ch4_trend_ppb>
    <uncertainty>1.24</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
  </row>
  <row>
    <month>2019-11</month>
    <year>2019</year>
    <decimal_date>2019.875</decimal_date>
    <ch4_ppb>1875.71</ch4_ppb>
    <ch4_trend_ppb>1870.15</ch4_trend_ppb>
    <uncertainty>1.24</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
  </row>
  <row>
    <month>2019-12</month>
    <year>2019</year>
    <decimal_date>2019.958</decimal_date>
    <ch4_ppb>1874.66</ch4_ppb>
    <ch4_trend_ppb>1871.12</ch4_trend_ppb>
    <uncertainty>0.95</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>2020-01</month>
    <year>2020</year>
    <decimal_date>2020.042</decimal_date>
    <ch4_ppb>1872.93</ch4_ppb>
    <ch4_trend_ppb>1872.15</ch4_trend_ppb>
    <uncertainty>1.23</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>2020-02</month>
    <year>2020</year>
    <decimal_date>2020.125</decimal_date>
    <ch4_ppb>1872.41</ch4_ppb>
    <ch4_trend_ppb>1873.19</ch4_trend_ppb>
    <uncertainty>1.15</uncertainty>
    <trend_uncertainty>0.64</trend_uncertainty>
  </row>
  <row>
    <month>2020-03</month>
    <year>2020</year>
    <decimal_date>2020.208</decimal_date>
    <ch4_ppb>1874.46</ch4_ppb>
    <ch4_trend_ppb>1874.27</ch4_trend_ppb>
    <uncertainty>0.83</uncertainty>
    <trend_uncertainty>0.65</trend_uncertainty>
  </row>
  <row>
    <month>2020-04</month>
    <year>2020</year>
    <decimal_date>2020.292</decimal_date>
    <ch4_ppb>1875.81</ch4_ppb>
    <ch4_trend_ppb>1875.41</ch4_trend_ppb>
    <uncertainty>1.22</uncertainty>
    <trend_uncertainty>0.66</trend_uncertainty>
  </row>
  <row>
    <month>2020-05</month>
    <year>2020</year>
    <decimal_date>2020.375</decimal_date>
    <ch4_ppb>1874.46</ch4_ppb>
    <ch4_trend_ppb>1876.59</ch4_trend_ppb>
    <uncertainty>1.15</uncertainty>
    <trend_uncertainty>0.67</trend_uncertainty>
  </row>
  <row>
    <month>2020-06</month>
    <year>2020</year>
    <decimal_date>2020.458</decimal_date>
    <ch4_ppb>1872.04</ch4_ppb>
    <ch4_trend_ppb>1877.8</ch4_trend_ppb>
    <uncertainty>1.23</uncertainty>
    <trend_uncertainty>0.67</trend_uncertainty>
  </row>
  <row>
    <month>2020-07</month>
    <year>2020</year>
    <decimal_date>2020.542</decimal_date>
    <ch4_ppb>1871.51</ch4_ppb>
    <ch4_trend_ppb>1879.05</ch4_trend_ppb>
    <uncertainty>1.34</uncertainty>
    <trend_uncertainty>0.66</trend_uncertainty>
  </row>
  <row>
    <month>2020-08</month>
    <year>2020</year>
    <decimal_date>2020.625</decimal_date>
    <ch4_ppb>1876.44</ch4_ppb>
    <ch4_trend_ppb>1880.34</ch4_trend_ppb>
    <uncertainty>1.27</uncertainty>
    <trend_uncertainty>0.65</trend_uncertainty>
  </row>
  <row>
    <month>2020-09</month>
    <year>2020</year>
    <decimal_date>2020.708</decimal_date>
    <ch4_ppb>1884.64</ch4_ppb>
    <ch4_trend_ppb>1881.65</ch4_trend_ppb>
    <uncertainty>1.11</uncertainty>
    <trend_uncertainty>0.63</trend_uncertainty>
  </row>
  <row>
    <month>2020-10</month>
    <year>2020</year>
    <decimal_date>2020.792</decimal_date>
    <ch4_ppb>1890.04</ch4_ppb>
    <ch4_trend_ppb>1882.98</ch4_trend_ppb>
    <uncertainty>1.03</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>2020-11</month>
    <year>2020</year>
    <decimal_date>2020.875</decimal_date>
    <ch4_ppb>1891.51</ch4_ppb>
    <ch4_trend_ppb>1884.34</ch4_trend_ppb>
    <uncertainty>0.88</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
  </row>
  <row>
    <month>2020-12</month>
    <year>2020</year>
    <decimal_date>2020.958</decimal_date>
    <ch4_ppb>1891.04</ch4_ppb>
    <ch4_trend_ppb>1885.72</ch4_trend_ppb>
    <uncertainty>1.06</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>2021-01</month>
    <year>2021</year>
    <decimal_date>2021.042</decimal_date>
    <ch4_ppb>1888.67</ch4_ppb>
    <ch4_trend_ppb>1887.16</ch4_trend_ppb>
    <uncertainty>1.43</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>2021-02</month>
    <year>2021</year>
    <decimal_date>2021.125</decimal_date>
    <ch4_ppb>1886.7</ch4_ppb>
    <ch4_trend_ppb>1888.55</ch4_trend_ppb>
    <uncertainty>1.02</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>2021-03</month>
    <year>2021</year>
    <decimal_date>2021.208</decimal_date>
    <ch4_ppb>1888.05</ch4_ppb>
    <ch4_trend_ppb>1889.96</ch4_trend_ppb>
    <uncertainty>0.91</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>2021-04</month>
    <year>2021</year>
    <decimal_date>2021.292</decimal_date>
    <ch4_ppb>1890.85</ch4_ppb>
    <ch4_trend_ppb>1891.43</ch4_trend_ppb>
    <uncertainty>0.65</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>2021-05</month>
    <year>2021</year>
    <decimal_date>2021.375</decimal_date>
    <ch4_ppb>1891.34</ch4_ppb>
    <ch4_trend_ppb>1892.93</ch4_trend_ppb>
    <uncertainty>0.74</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>2021-06</month>
    <year>2021</year>
    <decimal_date>2021.458</decimal_date>
    <ch4_ppb>1888.16</ch4_ppb>
    <ch4_trend_ppb>1894.44</ch4_trend_ppb>
    <uncertainty>0.75</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>2021-07</month>
    <year>2021</year>
    <decimal_date>2021.542</decimal_date>
    <ch4_ppb>1886.04</ch4_ppb>
    <ch4_trend_ppb>1895.95</ch4_trend_ppb>
    <uncertainty>0.71</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
  </row>
  <row>
    <month>2021-08</month>
    <year>2021</year>
    <decimal_date>2021.625</decimal_date>
    <ch4_ppb>1892.38</ch4_ppb>
    <ch4_trend_ppb>1897.49</ch4_trend_ppb>
    <uncertainty>1.31</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
  </row>
  <row>
    <month>2021-09</month>
    <year>2021</year>
    <decimal_date>2021.708</decimal_date>
    <ch4_ppb>1902.51</ch4_ppb>
    <ch4_trend_ppb>1899</ch4_trend_ppb>
    <uncertainty>1.43</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
  </row>
  <row>
    <month>2021-10</month>
    <year>2021</year>
    <decimal_date>2021.792</decimal_date>
    <ch4_ppb>1907.97</ch4_ppb>
    <ch4_trend_ppb>1900.5</ch4_trend_ppb>
    <uncertainty>0.83</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
  </row>
  <row>
    <month>2021-11</month>
    <year>2021</year>
    <decimal_date>2021.875</decimal_date>
    <ch4_ppb>1909.27</ch4_ppb>
    <ch4_trend_ppb>1901.97</ch4_trend_ppb>
    <uncertainty>1.29</uncertainty>
    <trend_uncertainty>0.65</trend_uncertainty>
  </row>
  <row>
    <month>2021-12</month>
    <year>2021</year>
    <decimal_date>2021.958</decimal_date>
    <ch4_ppb>1908.03</ch4_ppb>
    <ch4_trend_ppb>1903.41</ch4_trend_ppb>
    <uncertainty>1</uncertainty>
    <trend_uncertainty>0.68</trend_uncertainty>
  </row>
  <row>
    <month>2022-01</month>
    <year>2022</year>
    <decimal_date>2022.042</decimal_date>
    <ch4_ppb>1906.39</ch4_ppb>
    <ch4_trend_ppb>1904.83</ch4_trend_ppb>
    <uncertainty>1.24</uncertainty>
    <trend_uncertainty>0.72</trend_uncertainty>
  </row>
  <row>
    <month>2022-02</month>
    <year>2022</year>
    <decimal_date>2022.125</decimal_date>
    <ch4_ppb>1906.47</ch4_ppb>
    <ch4_trend_ppb>1906.14</ch4_trend_ppb>
    <uncertainty>1.55</uncertainty>
    <trend_uncertainty>0.77</trend_uncertainty>
  </row>
  <row>
    <month>2022-03</month>
    <year>2022</year>
    <decimal_date>2022.208</decimal_date>
    <ch4_ppb>1907.83</ch4_ppb>
    <ch4_trend_ppb>1907.4</ch4_trend_ppb>
    <uncertainty>1.62</uncertainty>
    <trend_uncertainty>0.8</trend_uncertainty>
  </row>
  <row>
    <month>2022-04</month>
    <year>2022</year>
    <decimal_date>2022.292</decimal_date>
    <ch4_ppb>1908.89</ch4_ppb>
    <ch4_trend_ppb>1908.66</ch4_trend_ppb>
    <uncertainty>1.1</uncertainty>
    <trend_uncertainty>0.85</trend_uncertainty>
  </row>
  <row>
    <month>2022-05</month>
    <year>2022</year>
    <decimal_date>2022.375</decimal_date>
    <ch4_ppb>1907.55</ch4_ppb>
    <ch4_trend_ppb>1909.85</ch4_trend_ppb>
    <uncertainty>1.18</uncertainty>
    <trend_uncertainty>0.88</trend_uncertainty>
  </row>
  <row>
    <month>2022-06</month>
    <year>2022</year>
    <decimal_date>2022.458</decimal_date>
    <ch4_ppb>1904.89</ch4_ppb>
    <ch4_trend_ppb>1910.99</ch4_trend_ppb>
    <uncertainty>1.49</uncertainty>
    <trend_uncertainty>0.92</trend_uncertainty>
  </row>
  <row>
    <month>2022-07</month>
    <year>2022</year>
    <decimal_date>2022.542</decimal_date>
    <ch4_ppb>1904.04</ch4_ppb>
    <ch4_trend_ppb>1912.07</ch4_trend_ppb>
    <uncertainty>1.73</uncertainty>
    <trend_uncertainty>0.94</trend_uncertainty>
  </row>
  <row>
    <month>2022-08</month>
    <year>2022</year>
    <decimal_date>2022.625</decimal_date>
    <ch4_ppb>1908.37</ch4_ppb>
    <ch4_trend_ppb>1913.11</ch4_trend_ppb>
    <uncertainty>1.86</uncertainty>
    <trend_uncertainty>0.96</trend_uncertainty>
  </row>
  <row>
    <month>2022-09</month>
    <year>2022</year>
    <decimal_date>2022.708</decimal_date>
    <ch4_ppb>1915.11</ch4_ppb>
    <ch4_trend_ppb>1914.08</ch4_trend_ppb>
    <uncertainty>1.49</uncertainty>
    <trend_uncertainty>0.97</trend_uncertainty>
  </row>
  <row>
    <month>2022-10</month>
    <year>2022</year>
    <decimal_date>2022.792</decimal_date>
    <ch4_ppb>1919.51</ch4_ppb>
    <ch4_trend_ppb>1915.01</ch4_trend_ppb>
    <uncertainty>1.32</uncertainty>
    <trend_uncertainty>0.96</trend_uncertainty>
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    <year>2022</year>
    <decimal_date>2022.875</decimal_date>
    <ch4_ppb>1922.31</ch4_ppb>
    <ch4_trend_ppb>1915.88</ch4_trend_ppb>
    <uncertainty>1.18</uncertainty>
    <trend_uncertainty>0.95</trend_uncertainty>
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    <month>2022-12</month>
    <year>2022</year>
    <decimal_date>2022.958</decimal_date>
    <ch4_ppb>1922.21</ch4_ppb>
    <ch4_trend_ppb>1916.72</ch4_trend_ppb>
    <uncertainty>1.53</uncertainty>
    <trend_uncertainty>0.92</trend_uncertainty>
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    <month>2023-01</month>
    <year>2023</year>
    <decimal_date>2023.042</decimal_date>
    <ch4_ppb>1920.01</ch4_ppb>
    <ch4_trend_ppb>1917.53</ch4_trend_ppb>
    <uncertainty>1.88</uncertainty>
    <trend_uncertainty>0.88</trend_uncertainty>
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  <row>
    <month>2023-02</month>
    <year>2023</year>
    <decimal_date>2023.125</decimal_date>
    <ch4_ppb>1918.98</ch4_ppb>
    <ch4_trend_ppb>1918.27</ch4_trend_ppb>
    <uncertainty>1.43</uncertainty>
    <trend_uncertainty>0.84</trend_uncertainty>
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    <month>2023-03</month>
    <year>2023</year>
    <decimal_date>2023.208</decimal_date>
    <ch4_ppb>1918.78</ch4_ppb>
    <ch4_trend_ppb>1918.99</ch4_trend_ppb>
    <uncertainty>1.05</uncertainty>
    <trend_uncertainty>0.8</trend_uncertainty>
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    <month>2023-04</month>
    <year>2023</year>
    <decimal_date>2023.292</decimal_date>
    <ch4_ppb>1919.66</ch4_ppb>
    <ch4_trend_ppb>1919.7</ch4_trend_ppb>
    <uncertainty>1.02</uncertainty>
    <trend_uncertainty>0.76</trend_uncertainty>
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    <month>2023-05</month>
    <year>2023</year>
    <decimal_date>2023.375</decimal_date>
    <ch4_ppb>1919.04</ch4_ppb>
    <ch4_trend_ppb>1920.4</ch4_trend_ppb>
    <uncertainty>1</uncertainty>
    <trend_uncertainty>0.72</trend_uncertainty>
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    <month>2023-06</month>
    <year>2023</year>
    <decimal_date>2023.458</decimal_date>
    <ch4_ppb>1915.05</ch4_ppb>
    <ch4_trend_ppb>1921.08</ch4_trend_ppb>
    <uncertainty>1.3</uncertainty>
    <trend_uncertainty>0.69</trend_uncertainty>
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  <row>
    <month>2023-07</month>
    <year>2023</year>
    <decimal_date>2023.542</decimal_date>
    <ch4_ppb>1912.96</ch4_ppb>
    <ch4_trend_ppb>1921.75</ch4_trend_ppb>
    <uncertainty>1.41</uncertainty>
    <trend_uncertainty>0.66</trend_uncertainty>
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    <month>2023-08</month>
    <year>2023</year>
    <decimal_date>2023.625</decimal_date>
    <ch4_ppb>1916.75</ch4_ppb>
    <ch4_trend_ppb>1922.42</ch4_trend_ppb>
    <uncertainty>1.4</uncertainty>
    <trend_uncertainty>0.65</trend_uncertainty>
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    <month>2023-09</month>
    <year>2023</year>
    <decimal_date>2023.708</decimal_date>
    <ch4_ppb>1924.47</ch4_ppb>
    <ch4_trend_ppb>1923.08</ch4_trend_ppb>
    <uncertainty>1.02</uncertainty>
    <trend_uncertainty>0.64</trend_uncertainty>
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    <month>2023-10</month>
    <year>2023</year>
    <decimal_date>2023.792</decimal_date>
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    <ch4_trend_ppb>1923.74</ch4_trend_ppb>
    <uncertainty>0.88</uncertainty>
    <trend_uncertainty>0.63</trend_uncertainty>
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    <month>2023-11</month>
    <year>2023</year>
    <decimal_date>2023.875</decimal_date>
    <ch4_ppb>1931.58</ch4_ppb>
    <ch4_trend_ppb>1924.41</ch4_trend_ppb>
    <uncertainty>0.76</uncertainty>
    <trend_uncertainty>0.63</trend_uncertainty>
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    <month>2023-12</month>
    <year>2023</year>
    <decimal_date>2023.958</decimal_date>
    <ch4_ppb>1931.23</ch4_ppb>
    <ch4_trend_ppb>1925.08</ch4_trend_ppb>
    <uncertainty>1.06</uncertainty>
    <trend_uncertainty>0.63</trend_uncertainty>
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    <month>2024-01</month>
    <year>2024</year>
    <decimal_date>2024.042</decimal_date>
    <ch4_ppb>1928.26</ch4_ppb>
    <ch4_trend_ppb>1925.77</ch4_trend_ppb>
    <uncertainty>0.99</uncertainty>
    <trend_uncertainty>0.63</trend_uncertainty>
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    <month>2024-02</month>
    <year>2024</year>
    <decimal_date>2024.125</decimal_date>
    <ch4_ppb>1925.64</ch4_ppb>
    <ch4_trend_ppb>1926.45</ch4_trend_ppb>
    <uncertainty>1.19</uncertainty>
    <trend_uncertainty>0.63</trend_uncertainty>
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    <month>2024-03</month>
    <year>2024</year>
    <decimal_date>2024.208</decimal_date>
    <ch4_ppb>1926.91</ch4_ppb>
    <ch4_trend_ppb>1927.14</ch4_trend_ppb>
    <uncertainty>0.82</uncertainty>
    <trend_uncertainty>0.62</trend_uncertainty>
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    <month>2024-04</month>
    <year>2024</year>
    <decimal_date>2024.292</decimal_date>
    <ch4_ppb>1928.32</ch4_ppb>
    <ch4_trend_ppb>1927.85</ch4_trend_ppb>
    <uncertainty>0.75</uncertainty>
    <trend_uncertainty>0.61</trend_uncertainty>
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    <month>2024-05</month>
    <year>2024</year>
    <decimal_date>2024.375</decimal_date>
    <ch4_ppb>1925.53</ch4_ppb>
    <ch4_trend_ppb>1928.56</ch4_trend_ppb>
    <uncertainty>0.75</uncertainty>
    <trend_uncertainty>0.6</trend_uncertainty>
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    <month>2024-06</month>
    <year>2024</year>
    <decimal_date>2024.458</decimal_date>
    <ch4_ppb>1921.44</ch4_ppb>
    <ch4_trend_ppb>1929.27</ch4_trend_ppb>
    <uncertainty>1.25</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
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  <row>
    <month>2024-07</month>
    <year>2024</year>
    <decimal_date>2024.542</decimal_date>
    <ch4_ppb>1920.43</ch4_ppb>
    <ch4_trend_ppb>1929.98</ch4_trend_ppb>
    <uncertainty>1.2</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
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  <row>
    <month>2024-08</month>
    <year>2024</year>
    <decimal_date>2024.625</decimal_date>
    <ch4_ppb>1924.88</ch4_ppb>
    <ch4_trend_ppb>1930.69</ch4_trend_ppb>
    <uncertainty>1.29</uncertainty>
    <trend_uncertainty>0.57</trend_uncertainty>
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  <row>
    <month>2024-09</month>
    <year>2024</year>
    <decimal_date>2024.708</decimal_date>
    <ch4_ppb>1934.33</ch4_ppb>
    <ch4_trend_ppb>1931.36</ch4_trend_ppb>
    <uncertainty>1.14</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
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  <row>
    <month>2024-10</month>
    <year>2024</year>
    <decimal_date>2024.792</decimal_date>
    <ch4_ppb>1940.74</ch4_ppb>
    <ch4_trend_ppb>1932.01</ch4_trend_ppb>
    <uncertainty>0.79</uncertainty>
    <trend_uncertainty>0.54</trend_uncertainty>
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  <row>
    <month>2024-11</month>
    <year>2024</year>
    <decimal_date>2024.875</decimal_date>
    <ch4_ppb>1940.13</ch4_ppb>
    <ch4_trend_ppb>1932.62</ch4_trend_ppb>
    <uncertainty>0.92</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
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  <row>
    <month>2024-12</month>
    <year>2024</year>
    <decimal_date>2024.958</decimal_date>
    <ch4_ppb>1937.73</ch4_ppb>
    <ch4_trend_ppb>1933.2</ch4_trend_ppb>
    <uncertainty>0.9</uncertainty>
    <trend_uncertainty>0.52</trend_uncertainty>
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  <row>
    <month>2025-01</month>
    <year>2025</year>
    <decimal_date>2025.042</decimal_date>
    <ch4_ppb>1935.89</ch4_ppb>
    <ch4_trend_ppb>1933.73</ch4_trend_ppb>
    <uncertainty>1.07</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
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  <row>
    <month>2025-02</month>
    <year>2025</year>
    <decimal_date>2025.125</decimal_date>
    <ch4_ppb>1934.5</ch4_ppb>
    <ch4_trend_ppb>1934.2</ch4_trend_ppb>
    <uncertainty>0.95</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
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  <row>
    <month>2025-03</month>
    <year>2025</year>
    <decimal_date>2025.208</decimal_date>
    <ch4_ppb>1934.04</ch4_ppb>
    <ch4_trend_ppb>1934.63</ch4_trend_ppb>
    <uncertainty>0.78</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
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  <row>
    <month>2025-04</month>
    <year>2025</year>
    <decimal_date>2025.292</decimal_date>
    <ch4_ppb>1934.67</ch4_ppb>
    <ch4_trend_ppb>1935.02</ch4_trend_ppb>
    <uncertainty>0.74</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
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  <row>
    <month>2025-05</month>
    <year>2025</year>
    <decimal_date>2025.375</decimal_date>
    <ch4_ppb>1933.35</ch4_ppb>
    <ch4_trend_ppb>1935.39</ch4_trend_ppb>
    <uncertainty>0.93</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
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  <row>
    <month>2025-06</month>
    <year>2025</year>
    <decimal_date>2025.458</decimal_date>
    <ch4_ppb>1929.17</ch4_ppb>
    <ch4_trend_ppb>1935.73</ch4_trend_ppb>
    <uncertainty>0.74</uncertainty>
    <trend_uncertainty>0.5</trend_uncertainty>
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  <row>
    <month>2025-07</month>
    <year>2025</year>
    <decimal_date>2025.542</decimal_date>
    <ch4_ppb>1927.36</ch4_ppb>
    <ch4_trend_ppb>1936.05</ch4_trend_ppb>
    <uncertainty>0.73</uncertainty>
    <trend_uncertainty>0.51</trend_uncertainty>
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  <row>
    <month>2025-08</month>
    <year>2025</year>
    <decimal_date>2025.625</decimal_date>
    <ch4_ppb>1931.55</ch4_ppb>
    <ch4_trend_ppb>1936.38</ch4_trend_ppb>
    <uncertainty>0.92</uncertainty>
    <trend_uncertainty>0.52</trend_uncertainty>
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  <row>
    <month>2025-09</month>
    <year>2025</year>
    <decimal_date>2025.708</decimal_date>
    <ch4_ppb>1939.25</ch4_ppb>
    <ch4_trend_ppb>1936.72</ch4_trend_ppb>
    <uncertainty>1.2</uncertainty>
    <trend_uncertainty>0.53</trend_uncertainty>
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  <row>
    <month>2025-10</month>
    <year>2025</year>
    <decimal_date>2025.792</decimal_date>
    <ch4_ppb>1944.98</ch4_ppb>
    <ch4_trend_ppb>1937.09</ch4_trend_ppb>
    <uncertainty>0.86</uncertainty>
    <trend_uncertainty>0.55</trend_uncertainty>
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  <row>
    <month>2025-11</month>
    <year>2025</year>
    <decimal_date>2025.875</decimal_date>
    <ch4_ppb>1945.51</ch4_ppb>
    <ch4_trend_ppb>1937.5</ch4_trend_ppb>
    <uncertainty>0.63</uncertainty>
    <trend_uncertainty>0.56</trend_uncertainty>
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  <row>
    <month>2025-12</month>
    <year>2025</year>
    <decimal_date>2025.958</decimal_date>
    <ch4_ppb>1942.64</ch4_ppb>
    <ch4_trend_ppb>1937.97</ch4_trend_ppb>
    <uncertainty>1.13</uncertainty>
    <trend_uncertainty>0.58</trend_uncertainty>
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  <row>
    <month>2026-01</month>
    <year>2026</year>
    <decimal_date>2026.042</decimal_date>
    <ch4_ppb>1940.79</ch4_ppb>
    <ch4_trend_ppb>1938.51</ch4_trend_ppb>
    <uncertainty>1.03</uncertainty>
    <trend_uncertainty>0.59</trend_uncertainty>
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  <row>
    <month>2026-02</month>
    <year>2026</year>
    <decimal_date>2026.125</decimal_date>
    <ch4_ppb>1939.48</ch4_ppb>
    <ch4_trend_ppb>1939.08</ch4_trend_ppb>
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  <row>
    <month>2026-03</month>
    <year>2026</year>
    <decimal_date>2026.208</decimal_date>
    <ch4_ppb>1936.88</ch4_ppb>
    <ch4_trend_ppb>1939.73</ch4_trend_ppb>
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  <row>
    <month>2026-04</month>
    <year>2026</year>
    <decimal_date>2026.292</decimal_date>
    <ch4_ppb>1937.57</ch4_ppb>
    <ch4_trend_ppb>1940.46</ch4_trend_ppb>
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  <row>
    <month>2026-05</month>
    <year>2026</year>
    <decimal_date>2026.375</decimal_date>
    <ch4_ppb>1939.61</ch4_ppb>
    <ch4_trend_ppb>1941.27</ch4_trend_ppb>
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  <row>
    <month>2026-06</month>
    <year>2026</year>
    <decimal_date>2026.458</decimal_date>
    <ch4_ppb>1934.57</ch4_ppb>
    <ch4_trend_ppb>1942.12</ch4_trend_ppb>
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</dataset>
