| Characteristics | Size n Percentage (%) |
| Sex |
|
| F | 5902 (48.9) |
| M | 6158 (51.1) |
| Age |
|
| 6 | 5902 (48.9) |
| 7 | 6158 (51.1) |
| Treated before |
|
| Yes | 9395 (77.9) |
| No | 2614 (21.7) |
| Unknown | 51 (0.4) |