| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
1 | | | | | | | 30.5 | 34.8 | 30.6 | 22.4 | 20.6 | 14.1 |
2 | | | | | | | 33.3 | 34.7 | 28.4 | 23.0 | 20.0 | 13.6 |
3 | | | | | | | 35.2 | 35.4 | 27.0 | 25.5 | 21.9 | 10.8 |
4 | | | | | | | 34.1 | 35.7 | 30.2 | 25.8 | 20.3 | 12.7 |
5 | | | | | | | 31.4 | 33.8 | 31.8 | 25.3 | 20.4 | 14.2 |
6 | | | | | | | 33.2 | 35.9 | 30.6 | 25.8 | 19.7 | 11.9 |
7 | | | | | | | 31.8 | 36.3 | 31.8 | 26.0 | 20.3 | 16.3 |
8 | | | | | | | 31.0 | 34.2 | 29.0 | 24.2 | 20.7 | 14.1 |
9 | | | | | | | 30.5 | 33.6 | 29.3 | 23.5 | 18.6 | 14.7 |
10 | | | | | | | 30.3 | 33.9 | 27.7 | 25.4 | 21.4 | 14.4 |
11 | | | | | | | 30.9 | | 28.4 | 25.9 | 22.3 | 12.4 |
12 | | | | | | | 30.8 | | 29.7 | 25.1 | 14.7 | 10.4 |
13 | | | | | | | 33.4 | 33.7 | 28.5 | 24.9 | 19.3 | 8.7 |
14 | | | | | | | 32.9 | 31.1 | 28.4 | 23.9 | 18.3 | 10.7 |
15 | | | | | | | 32.4 | 30.7 | 27.7 | 21.6 | 12.9 | 14.8 |
16 | | | | | | | 33.1 | 31.4 | 26.6 | 24.6 | 17.4 | 13.9 |
17 | | | | | | | 36.4 | 31.7 | 23.3 | 27.0 | 17.2 | 15.6 |
18 | | | | | | | 36.6 | 27.8 | 25.3 | 24.3 | 19.9 | 15.1 |
19 | | | | | | | 37.7 | 27.6 | 25.8 | 26.3 | 15.3 | 10.7 |
20 | | | | | | | 36.9 | 27.4 | 26.3 | 26.9 | 17.8 | 13.0 |
21 | | | | | | | 33.9 | 29.6 | 25.2 | 21.9 | 15.8 | 12.9 |
22 | | | | | | | 35.1 | 32.5 | 23.4 | 22.1 | 11.3 | 14.6 |
23 | | | | | | | 33.7 | 31.3 | 23.9 | 24.9 | 17.1 | 15.9 |
24 | | | | | | | 29.6 | 31.3 | 20.1 | 24.8 | 18.2 | 17.0 |
25 | | | | | | | 29.6 | 31.9 | 24.0 | 23.6 | 11.9 | 16.8 |
26 | | | | | | | 29.6 | | 23.5 | 24.4 | 16.7 | 16.3 |
27 | | | | | | 34.8 | 33.4 | | 21.8 | 26.2 | 16.9 | 16.7 |
28 | | | | | | 30.4 | 33.6 | | 20.7 | 26.1 | 10.4 | 16.1 |
29 | | | | | | 28.2 | 32.2 | | 22.0 | 26.6 | 10.2 | 14.8 |
30 | | | | | | 19.4 | 32.0 | 30.8 | 17.8 | 24.6 | 13.5 | 15.2 |
31 | | | | | | | 33.3 | 28.9 | | 24.4 | | 14.3 |