JanFebMarAprMayJunJulAugSepOctNovDec
17.66.6-1.25.315.023.729.124.024.613.210.2 
29.17.10.83.412.620.827.228.525.817.911.3 
38.33.60.314.216.026.824.825.722.615.512.9 
49.85.62.612.319.417.528.125.816.618.612.7 
55.23.99.212.924.221.129.628.719.816.910.9 
65.32.17.914.525.417.229.827.116.210.714.5 
75.24.99.213.027.422.929.628.216.612.413.7 
83.17.87.512.424.716.329.621.816.517.111.4 
94.16.810.212.718.223.1 20.418.618.810.7 
105.58.712.87.517.323.9 18.217.922.712.1 
117.86.112.27.616.925.2 22.118.119.612.0 
126.25.36.65.817.120.1 19.718.218.913.1 
135.94.610.610.121.022.5 25.118.322.313.0 
144.06.012.116.124.121.2 22.315.917.813.5 
159.37.88.113.025.918.8 24.817.810.412.7 
163.67.810.614.313.819.8 20.221.717.012.5 
174.78.91.614.415.918.0 18.123.315.4  
187.47.60.322.719.722.8 25.721.913.3  
195.310.86.227.522.522.1 21.720.115.3  
203.311.17.822.224.421.718.823.216.517.6  
216.67.49.221.825.121.423.924.316.218.1  
228.23.910.618.921.426.327.724.412.613.0  
2312.63.410.915.421.323.330.818.115.414.2  
2412.87.110.812.222.828.926.915.815.315.0  
258.95.613.713.013.331.127.119.916.314.2  
268.22.313.314.221.930.632.715.722.910.7  
2712.01.411.48.126.6 29.718.122.26.3  
2813.6-2.18.89.225.022.821.718.115.79.1  
2910.88.212.222.428.320.920.116.17.4  
306.910.111.114.526.024.720.113.69.0  
316.94.421.223.221.210.7 
Avg: 7.45.88.013.320.5* 22.9* 26.822.218.414.8* 12.3 
Hi: 13.611.113.727.527.4* 31.1* 32.728.725.822.7* 14.5 
Lo: 3.1-2.1-1.23.412.6* 16.3* 18.815.712.66.3* 10.2 
Note:  *Incomplete dataset.
AvgJanFebMarAprMayJunJulAugSepOctNovDec
20187.45.88.013.320.5* 22.9* 26.822.218.414.8* 12.3 
2017* 7.5 * 13.2* 14.718.620.922.120.717.815.810.1* 7.6
2016   * 13.3* 17.6* 20.1* 22.5* 22.520.8* 14.6* 9.4* 9.4
2015* 8.4* 7.910.7* 15.8* 15.8* 20.421.421.418.1* 17.0 * 13.1
20148.1* 9.412.9* 15.5* 16.320.524.520.419.9* 15.5* 11.88.4
2013* 8.0* 7.3* 7.2* 12.8* 15.8* 19.9* 25.122.218.6* 16.0* 9.9* 9.6
2012* 8.48.4* 20.111.8* 14.3* 17.7* 19.9* 21.3* 18.6* 13.1* 8.8* 7.5
20117.3* 10.1* 12.2* 18.4* 17.420.321.9* 21.3* 20.4* 16.6* 12.3* 8.4
2010* 4.5* 6.613.3* 15.7* 16.3* 21.521.820.5* 18.914.68.2* 3.3
2009* 6.37.7* 12.7* 16.4* 18.1* 21.3* 22.222.9* 20.5* 16.6* 11.3* 6.0
2008* 9.3* 10.1* 11.215.1* 21.3* 21.0* 24.3* 23.4* 20.2* 12.3* 9.9* 6.5
2007    * 17.6* 17.4* 20.2* 21.2* 17.3* 15.511.2* 7.4
Avg