| Jan | Feb | March | April | May | June | July | Aug | Sept | Oct | Nov | Dec |
1 | 25.3 | 21.6 | | | | | | | | | | |
2 | 26.5 | 21.8 | | | | | | | | | | |
3 | 27.4 | 21.7 | | | | | | | | | | |
4 | 27.4 | 20.3 | | | | | | | | | | |
5 | 27.6 | 19.1 | | | | | | | | | | |
6 | 26.0 | 18.7 | | | | | | | | | | |
7 | 27.5 | 21.1 | | | | | | | | | | |
8 | 27.1 | 25.1 | | | | | | | | | | |
9 | 21.3 | 26.6 | | | | | | | | | | |
10 | 31.3 | 25.3 | | | | | | | | | | |
11 | 24.5 | 26.5 | | | | | | | | | | |
12 | 24.3 | 22.7 | | | | | | | | | | |
13 | 25.0 | 23.6 | | | | | | | | | | |
14 | 24.4 | 26.8 | | | | | | | | | | |
15 | 24.1 | 24.9 | | | | | | | | | | |
16 | 26.1 | 18.8 | | | | | | | | | | |
17 | 30.3 | 19.1 | | | | | | | | | | |
18 | 26.4 | 19.7 | | | | | | | | | | |
19 | 27.9 | 23.6 | | | | | | | | | | |
20 | 23.4 | 26.6 | | | | | | | | | | |
21 | 24.1 | 32.2 | | | | | | | | | | |
22 | 23.4 | 30.9 | | | | | | | | | | |
23 | 27.1 | 30.5 | | | | | | | | | | |
24 | 30.2 | 28.5 | | | | | | | | | | |
25 | 27.7 | 26.0 | | | | | | | | | | |
26 | 29.4 | 24.6 | | | | | | | | | | |
27 | 34.2 | 25.1 | | | | | | | | | | |
28 | 33.8 | 25.1 | | | | | | | | | | |
29 | 19.8 | | | | | | | | | | | |
30 | 19.3 | | | | | | | | | | | |
31 | 20.4 | | | | | | | | | | | |
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