Cumulative cannabis and tobacco use up to age 32 yrs
| Cannabis joint-yrs | Total | |||
| 0 | ≤1 | >1 | ||
| Tobacco pack-yrs | ||||
| 0 | 226 | 208 | 40 | 474 (49.0) |
| ≤10 | 35 | 171 | 72 | 278 (28.8) |
| >10 | 23 | 82 | 110 | 215 (22.2) |
| Total | 284 (29.4) | 461 (47.7) | 222 (23.0) | 967 |
Percentage values are given in parentheses. Chi-squared (4) = 242, p<0.001.