| Characteristics | Groups | ||
| I | II | III | |
| Sex | |||
| Male | 2 | 2 | 3 |
| Female | (-) | 1 | 1 |
| Age (years) | |||
| Average | 29 | 20.3 | 28.5 |
| Range | 19 - 39 | 18 - 22 | 13 - 51 |