| Jan | Feb | March | April | May | June | July | Aug | Sept | Oct | Nov | Dec |
|---|
| 1 | 17.2 | 14.2 | | | | | | | | | | |
|---|
| 2 | 16.6 | 17.6 | | | | | | | | | | |
|---|
| 3 | 13.8 | 18.5 | | | | | | | | | | |
|---|
| 4 | 12.2 | 15.3 | | | | | | | | | | |
|---|
| 5 | 10.0 | 12.9 | | | | | | | | | | |
|---|
| 6 | 14.3 | 11.8 | | | | | | | | | | |
|---|
| 7 | 17.2 | 13.0 | | | | | | | | | | |
|---|
| 8 | 16.8 | 15.5 | | | | | | | | | | |
|---|
| 9 | 15.9 | 16.5 | | | | | | | | | | |
|---|
| 10 | 16.9 | 17.7 | | | | | | | | | | |
|---|
| 11 | 20.2 | 16.9 | | | | | | | | | | |
|---|
| 12 | 18.0 | 17.1 | | | | | | | | | | |
|---|
| 13 | 16.2 | 20.3 | | | | | | | | | | |
|---|
| 14 | 18.6 | 16.7 | | | | | | | | | | |
|---|
| 15 | 17.9 | 11.9 | | | | | | | | | | |
|---|
| 16 | 17.7 | 7.8 | | | | | | | | | | |
|---|
| 17 | 13.7 | | | | | | | | | | | |
|---|
| 18 | 11.1 | | | | | | | | | | | |
|---|
| 19 | 15.5 | | | | | | | | | | | |
|---|
| 20 | 14.9 | | | | | | | | | | | |
|---|
| 21 | 15.0 | | | | | | | | | | | |
|---|
| 22 | 16.0 | | | | | | | | | | | |
|---|
| 23 | 16.0 | | | | | | | | | | | |
|---|
| 24 | 16.3 | | | | | | | | | | | |
|---|
| 25 | 17.8 | | | | | | | | | | | |
|---|
| 26 | 16.1 | | | | | | | | | | | |
|---|
| 27 | 12.2 | | | | | | | | | | | |
|---|
| 28 | 16.8 | | | | | | | | | | | |
|---|
| 29 | 14.5 | | | | | | | | | | | |
|---|
| 30 | 17.2 | | | | | | | | | | | |
|---|
| 31 | 14.7 | | | | | | | | | | | |
|---|
|
