| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
1 | 6.6 | 14.3 | 2.9 | 11.4 | 10.8 | 14.9 | 11.9 | 16.7 | 14.4 | 17.1 | | | | | | | | | | | | | | |
2 | 4.2 | 13.8 | 0.2 | 17.4 | 8.8 | 15.8 | 10.4 | 17.7 | 10.1 | 15.0 | | | | | | | | | | | | | | |
3 | 12.3 | 14.8 | 1.7 | 17.2 | 7.7 | 15.4 | 9.4 | 18.3 | 7.8 | 17.9 | | | | | | | | | | | | | | |
4 | 8.0 | 16.0 | 6.7 | 15.8 | 6.4 | 15.4 | 9.3 | 17.1 | 9.6 | 20.1 | | | | | | | | | | | | | | |
5 | 10.6 | 14.4 | 6.5 | 13.8 | 5.0 | 15.7 | 6.8 | 18.9 | 10.1 | 21.3 | | | | | | | | | | | | | | |
6 | 9.9 | 14.2 | 10.2 | 15.8 | 4.7 | 14.4 | 7.4 | 21.7 | | | | | | | | | | | | | | | | |
7 | 7.8 | 11.7 | 10.4 | 13.4 | 1.8 | 15.3 | 7.1 | 22.2 | | | | | | | | | | | | | | | | |
8 | 7.8 | 13.0 | 10.7 | 13.9 | 2.2 | 15.6 | 8.8 | 23.6 | | | | | | | | | | | | | | | | |
9 | 2.8 | 12.2 | 11.3 | 15.0 | 6.7 | 16.8 | 8.3 | 21.9 | | | | | | | | | | | | | | | | |
10 | 1.6 | 10.2 | 11.0 | 14.3 | 8.3 | 14.4 | 11.2 | 17.5 | | | | | | | | | | | | | | | | |
11 | 1.3 | 13.1 | 7.8 | 14.1 | 4.6 | 15.9 | 10.2 | 20.8 | | | | | | | | | | | | | | | | |
12 | -2.0 | 14.1 | 4.8 | 15.8 | 3.8 | 16.6 | 9.1 | 24.0 | | | | | | | | | | | | | | | | |
13 | -1.2 | 11.4 | 3.3 | 16.2 | 5.2 | 18.1 | 9.8 | 28.3 | | | | | | | | | | | | | | | | |
14 | 6.7 | 11.9 | 2.3 | 16.6 | 4.4 | 17.3 | 10.9 | 25.6 | | | | | | | | | | | | | | | | |
15 | 3.8 | 14.1 | 2.0 | 15.9 | 8.1 | 14.6 | 9.9 | 24.4 | | | | | | | | | | | | | | | | |
16 | 3.2 | 14.2 | 4.6 | 17.5 | 9.3 | 18.5 | 10.4 | 18.7 | | | | | | | | | | | | | | | | |
17 | 8.7 | 14.7 | 4.7 | 20.1 | 6.8 | 18.0 | 6.7 | 19.6 | | | | | | | | | | | | | | | | |
18 | 12.9 | 15.6 | 2.9 | 17.9 | 9.6 | 13.5 | 6.7 | 13.3 | | | | | | | | | | | | | | | | |
19 | 8.2 | 15.2 | 5.2 | 15.9 | 8.8 | 20.4 | 5.9 | 18.2 | | | | | | | | | | | | | | | | |
20 | 0.7 | 9.7 | 5.4 | 19.8 | 6.7 | 21.4 | 7.4 | 19.7 | | | | | | | | | | | | | | | | |
21 | -3.5 | 12.8 | 2.5 | 19.3 | 6.1 | 18.4 | 3.7 | 17.3 | | | | | | | | | | | | | | | | |
22 | -3.5 | 13.4 | 4.3 | 14.4 | 6.4 | 21.8 | 5.9 | 12.9 | | | | | | | | | | | | | | | | |
23 | 5.8 | 16.2 | 9.9 | 13.6 | 6.6 | 16.0 | 6.4 | 11.3 | | | | | | | | | | | | | | | | |
24 | 2.7 | 11.3 | 6.4 | 12.1 | 5.9 | 18.4 | 4.1 | 16.1 | | | | | | | | | | | | | | | | |
25 | 5.2 | 14.2 | 3.6 | 14.6 | 3.2 | 18.5 | 4.9 | 16.3 | | | | | | | | | | | | | | | | |
26 | 9.4 | 13.8 | 6.6 | 12.7 | 8.9 | 15.8 | 6.0 | 18.5 | | | | | | | | | | | | | | | | |
27 | 4.7 | 16.3 | 8.3 | 12.6 | 9.2 | 15.1 | 10.2 | 20.1 | | | | | | | | | | | | | | | | |
28 | 2.3 | 18.1 | 8.9 | 18.9 | 10.2 | 16.5 | 10.5 | 25.1 | | | | | | | | | | | | | | | | |
29 | 0.1 | 16.4 | 14.0 | 18.7 | 10.7 | 19.5 | 12.2 | 26.8 | | | | | | | | | | | | | | | | |
30 | -0.2 | 15.2 | | 10.3 | 21.6 | 12.1 | 28.5 | | | | | | | | | | | | | | | | |
31 | 0.9 | 14.9 | | 12.3 | 17.8 | | | | | | | | | | | | | | |