| Jan | Feb | March | April | May | June | July | Aug | Sept | Oct | Nov | Dec |
1 | 14.8 | 18.1 | 15.0 | | | | | | | | | |
2 | 14.3 | 17.9 | 12.1 | | | | | | | | | |
3 | 14.7 | 19.9 | 14.0 | | | | | | | | | |
4 | 15.5 | 18.0 | 15.4 | | | | | | | | | |
5 | 16.6 | 18.3 | 15.4 | | | | | | | | | |
6 | 16.8 | 18.5 | 12.9 | | | | | | | | | |
7 | 17.7 | 15.9 | 9.4 | | | | | | | | | |
8 | 17.5 | 13.9 | 8.1 | | | | | | | | | |
9 | 16.1 | 14.9 | 13.6 | | | | | | | | | |
10 | 15.4 | 13.2 | 15.6 | | | | | | | | | |
11 | 15.6 | 11.2 | 14.0 | | | | | | | | | |
12 | 14.1 | 13.2 | 13.5 | | | | | | | | | |
13 | 13.2 | 14.8 | 13.8 | | | | | | | | | |
14 | 14.2 | 15.0 | 10.7 | | | | | | | | | |
15 | 12.7 | 16.1 | 9.3 | | | | | | | | | |
16 | 12.5 | 13.6 | 10.0 | | | | | | | | | |
17 | 13.1 | 15.1 | 17.0 | | | | | | | | | |
18 | 12.6 | 14.3 | 16.7 | | | | | | | | | |
19 | 16.6 | 11.5 | 13.9 | | | | | | | | | |
20 | 15.5 | 13.2 | 12.7 | | | | | | | | | |
21 | 14.4 | 14.7 | 10.3 | | | | | | | | | |
22 | 16.6 | 17.0 | 9.6 | | | | | | | | | |
23 | 16.3 | 13.0 | 7.7 | | | | | | | | | |
24 | 15.7 | 14.2 | 8.9 | | | | | | | | | |
25 | 13.5 | 14.5 | 8.5 | | | | | | | | | |
26 | 12.3 | 15.0 | 15.7 | | | | | | | | | |
27 | 15.3 | 16.3 | 13.3 | | | | | | | | | |
28 | 17.5 | 14.6 | 8.9 | | | | | | | | | |
29 | 18.9 | | | | | | | | | | | |
30 | 17.9 | | | | | | | | | | | |
31 | 18.5 | | | | | | | | | | | |
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