Table 1 Demographic data for the three survey years.
| No. students | No. participants | Participation rate | Mean age | Median age | |
|---|---|---|---|---|---|
| Girls | |||||
| 1982 | 398 | 279 | 70% | 17.7 | 17 |
| 1996 | 330 | 247 | 79% | 18.0 | 18 |
| 2001 | 266 | 193 | 73% | 17.6 | 17 |
| Boys | |||||
| 1982 | 228 | 118 | 52% | 18.0 | 18 |
| 1996 | 169 | 94 | 56% | 18.1 | 18 |
| 2001 | 143 | 77 | 54% | 17.4 | 17 |