Relative frequency (percentage) of age distribution in the two study periods
| Age (years) | March 2019 (%) | March 2020 (%) |
| <1 | 12.9 | 19.1 |
| 1 | 13.1 | 12.1 |
| 2 | 11.3 | 10.7 |
| 3 | 10.4 | 7.6 |
| 4 | 8.8 | 9.6 |
| 5 | 7.0 | 4.4 |
| 6 | 6.0 | 5.8 |
| 7 | 5.1 | 3.6 |
| 8 | 4.8 | 4.3 |
| 9 | 5.0 | 3.9 |
| 10 | 4.4 | 4.7 |
| 11 | 3.6 | 3.2 |
| 12 | 3.2 | 4.3 |
| 13 | 2.8 | 3.7 |
| >13 | 1.7 | 3.0 |