JanFebMarAprMayJunJulAugSepOctNovDec
19.9           
25.3           
33.2           
45.4           
57.0           
611.2           
711.7           
88.1           
94.8           
109.7           
118.7           
1210.7           
1311.2           
148.3           
1510.2           
169.6           
174.3           
183.9           
192.8           
205.9           
21            
22            
23            
24            
25            
26            
27            
28            
29           
30           
31       
Avg: * 7.6           
Hi: * 11.7           
Lo: * 2.8           
Note:  *Incomplete dataset.
AvgJanFebMarAprMayJunJulAugSepOctNovDec
2019* 7.6           
20187.45.88.013.320.5* 22.9* 26.822.218.414.810.39.0
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