| Age Groups (years) | Age at Menarche (years) | ||||||
| 8 | 9 | 10 | 11 | 12 | 13 | 14 | |
| 7 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 8 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 9 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 10 | 1 | 1 | 1 | 0 | 0 | 0 | 0 |
| 11 | 0 | 3 | 8 | 10 | 0 | 0 | 0 |
| 12 | 0 | 2 | 17 | 62 | 34 | 0 | 0 |
| 13 | 0 | 3 | 11 | 37 | 43 | 9 | 0 |
| 14 | 1 | 3 | 8 | 38 | 48 | 44 | 10 |
| 15 | 0 | 1 | 5 | 19 | 34 | 20 | 3 |
| 16 | 0 | 0 | 0 | 3 | 6 | 4 | 3 |
| 17 | 0 | 0 | 0 | 0 | 1 | 0 | 0 |
| All groups | 2 | 13 | 50 | 169 | 166 | 77 | 16 |