| Age group (years) | No. of cases (n) | Median (Interquartile range) 25% - 75% | |
| Tn distance (cm) | Tm distance (cm) | ||
| less than 5 | 120 | 10 (9.5 - 10.5) | 4.5 (4 - 5) |
| 5 and above | 76 | 11 (10.5 - 11.5) | 5 (5 - 5.5) |