| Location | Month | 2000 | 2001 | 2002 | 2003 | 2004 |
|---|---|---|---|---|---|---|
| SWAN1 | 1 | 10 | 9 | 10 | 11 | |
| SWAN1 | 2 | 9 | 10 | 8 | 9 | |
| SWAN1 | 3 | 10 | 8 | 11 | 8 | |
| SWAN1 | 4 | 10 | 9 | 8 | 10 | |
| SWAN1 | 5 | 9 | 10 | 9 | 10 | |
| SWAN1 | 6 | 9 | 10 | 10 | 10 | |
| SWAN1 | 7 | 10 | 11 | 10 | 8 | |
| SWAN1 | 8 | 8 | 10 | 11 | 9 | |
| SWAN1 | 9 | 10 | 8 | 5 | 10 | |
| SWAN1 | 10 | 11 | 10 | 4 | 10 | |
| SWAN1 | 11 | 10 | 10 | 9 | 10 | |
| SWAN1 | 12 | 9 | 10 | 9 | 10 |