|  | 1982 |  | 1996 |  | 2001 |  |  |
---|---|---|---|---|---|---|---|---|
 | Age at first sexual intercourse | N (%) | 95% CI | N (%) | 95% CI | N (%) | 95% CI | Trend* |
Boys: | 11 | 0 (0) |  | 0 (0) |  | 1 (1) | (0–3) |  |
 | 12 | 0 (0) |  | 0 (0) |  | 0 (0) |  |  |
 | 13 | 3 (3) | (0–6) | 4 (4) | (0–8) | 4 (5) | (0–8) |  |
 | 14 | 8 (7) | (3–13) | 6 (6) | (2–10) | 11 (14) | (6–16) |  |
 | 15 | 17 (14) | (12–22) | 25 (27) | (20–30) | 15 (20) | (10–20) |  |
 | All ages < 16 | 28 (24) |  | 35 (37) |  | 31 (40) |  | χ2 = 7.5 p = 0.023 |
Girls: | 12 | 0 (0) |  | 1 (1) | (0–3) | 2 (1) | (0–5) |  |
 | 13 | 15 (5) | (8–22) | 8 (3) | (3–13) | 8 (4) | (3–13) |  |
 | 14 | 35 (13) | (25–45) | 20 (8) | (13–27) | 23 (12) | (15–31) |  |
 | 15 | 66 (24) | (56–76) | 42 (17) | (34–50) | 48 (25) | (39–57) |  |
 | All ages < 16 | 116 (42) |  | 71 (29) |  | 81 (42) |  | χ22 = 11.8 p = 0.003 |