| Jan | Feb | March | April | May | June | July | Aug | Sept | Oct | Nov | Dec |
|---|
| 1 | 17.0 | 20.7 | 17.6 | | | | | | | | | |
|---|
| 2 | 16.8 | 22.9 | 17.0 | | | | | | | | | |
|---|
| 3 | 18.3 | 23.7 | 19.4 | | | | | | | | | |
|---|
| 4 | 19.1 | 23.3 | 19.4 | | | | | | | | | |
|---|
| 5 | 19.5 | 23.5 | 17.8 | | | | | | | | | |
|---|
| 6 | 20.5 | 23.9 | 16.0 | | | | | | | | | |
|---|
| 7 | 19.0 | 21.3 | 14.6 | | | | | | | | | |
|---|
| 8 | 18.8 | 20.6 | 16.2 | | | | | | | | | |
|---|
| 9 | 18.1 | 19.2 | 20.1 | | | | | | | | | |
|---|
| 10 | 17.4 | 18.5 | 18.7 | | | | | | | | | |
|---|
| 11 | 20.1 | 16.3 | 17.7 | | | | | | | | | |
|---|
| 12 | 17.1 | 16.5 | 17.9 | | | | | | | | | |
|---|
| 13 | 16.1 | 16.7 | 18.8 | | | | | | | | | |
|---|
| 14 | 16.9 | 18.3 | 15.7 | | | | | | | | | |
|---|
| 15 | 17.7 | 18.9 | 14.9 | | | | | | | | | |
|---|
| 16 | 17.4 | 16.7 | 17.6 | | | | | | | | | |
|---|
| 17 | 18.8 | 17.4 | 21.5 | | | | | | | | | |
|---|
| 18 | 16.9 | 17.3 | 18.9 | | | | | | | | | |
|---|
| 19 | 17.9 | 18.0 | 15.2 | | | | | | | | | |
|---|
| 20 | 20.7 | 18.7 | 21.4 | | | | | | | | | |
|---|
| 21 | 18.8 | 20.9 | 18.1 | | | | | | | | | |
|---|
| 22 | 20.9 | 21.5 | 14.1 | | | | | | | | | |
|---|
| 23 | 18.7 | 16.1 | 13.6 | | | | | | | | | |
|---|
| 24 | 18.2 | 17.2 | 13.6 | | | | | | | | | |
|---|
| 25 | 18.2 | 16.7 | 12.7 | | | | | | | | | |
|---|
| 26 | 19.8 | 18.9 | 19.7 | | | | | | | | | |
|---|
| 27 | 19.6 | 17.2 | 18.8 | | | | | | | | | |
|---|
| 28 | 18.6 | 17.5 | 18.3 | | | | | | | | | |
|---|
| 29 | 23.2 | | | | | | | | | | | |
|---|
| 30 | 22.6 | | | | | | | | | | | |
|---|
| 31 | 21.2 | | | | | | | | | | | |
|---|
|
