| Jan | Feb | March | April | May | June | July | Aug | Sept | Oct | Nov | Dec |
1 | 16.0 | 21.0 | | | | | | | | | | |
2 | 17.2 | 19.1 | | | | | | | | | | |
3 | 17.0 | 17.4 | | | | | | | | | | |
4 | 14.2 | 18.9 | | | | | | | | | | |
5 | 8.7 | 16.7 | | | | | | | | | | |
6 | 8.2 | 14.3 | | | | | | | | | | |
7 | 11.6 | 14.4 | | | | | | | | | | |
8 | 12.6 | 14.7 | | | | | | | | | | |
9 | 10.3 | 20.2 | | | | | | | | | | |
10 | 10.0 | 19.6 | | | | | | | | | | |
11 | 11.6 | 18.0 | | | | | | | | | | |
12 | 9.5 | | | | | | | | | | | |
13 | 10.5 | | | | | | | | | | | |
14 | 10.9 | | | | | | | | | | | |
15 | 10.5 | | | | | | | | | | | |
16 | 10.6 | | | | | | | | | | | |
17 | 12.3 | | | | | | | | | | | |
18 | 12.6 | | | | | | | | | | | |
19 | 13.0 | | | | | | | | | | | |
20 | 13.1 | | | | | | | | | | | |
21 | 14.4 | | | | | | | | | | | |
22 | 10.3 | | | | | | | | | | | |
23 | 16.5 | | | | | | | | | | | |
24 | 14.4 | | | | | | | | | | | |
25 | 21.7 | | | | | | | | | | | |
26 | 20.5 | | | | | | | | | | | |
27 | 14.6 | | | | | | | | | | | |
28 | 12.2 | | | | | | | | | | | |
29 | 16.8 | | | | | | | | | | | |
30 | 19.0 | | | | | | | | | | | |
31 | 19.9 | | | | | | | | | | | |
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