Table 1.
National estimate of the percentage (and 95% confidence interval) of marijuana use among high school students, by year – National Youth Risk Behavior Survey, United States, 1999-2013
| Any Lifetime Use | Repeated Lifetime Use | Current Use | Repeated Past 30-Day Use | Frequent Use | Early Use | |
|---|---|---|---|---|---|---|
| 1999 | 47.2 (44.4, 50.1) | 37.7 (35.0, 40.4) | 26.7 (24.2, 29.3) | 17.7 (16.0, 19.6) | 7.9 (6.7, 9.2) | 11.3 (9.6, 13.2) |
| 2001 | 42.4 (40.5, 44.3) | 33.7 (31.9, 35.7) | 23.9 (22.4, 25.5) | 16.2 (14.7, 17.8) | 7.4 (6.3, 8.6) | 10.2 (9.1, 11.5) |
| 2003 | 40.2 (37.4, 43.2) | 31.5 (29.1, 34.1) | 22.4 (20.2, 24.7) | 15.1 (13.3, 17.1) | 6.9 (5.9, 8.0) | 9.9 (8.7, 11.3) |
| 2005 | 38.5 (36.1, 40.9) | 29.8 (27.6, 32.2) | 20.2 (18.6, 22.0) | 13.1 (11.8, 14.4) | 5.9 (5.2, 6.7) | 8.7 (7.8, 9.6) |
| 2007 | 38.1 (35.5, 40.8) | 28.8 (26.4, 31.3) | 19.7 (17.9, 21.7) | 12.4 (11.0, 14.0) | 5.4 (4.6, 6.3) | 8.3 (7.0, 9.7) |
| 2009 | 36.8 (34.8, 38.8) | 28.5 (26.8, 30.3) | 20.8 (19.5, 22.3) | 13.6 (12.5, 14.7) | 5.7 (5.2, 6.4) | 7.5 (6.7, 8.4) |
| 2011 | 39.9 (37.9, 42.0) | 32.2 (30.5, 33.9) | 23.1 (21.6, 24.6) | 15.7 (14.6, 16.9) | 7.2 (6.5, 8.0) | 8.1 (7.3, 9.0) |
| 2013 | 40.7 (37.9, 43.4) | 32.0 (29.6, 34.6) | 23.4 (21.4, 25.6) | 16.3 (14.5, 18.2) | 7.4 (6.6, 8.3) | 8.6 (7.5, 10.0) |
| All Years | 40.5 (39.5, 41.4) | 31.8 (31.0, 32.6) | 22.5 (21.8, 23.3) | 15.0 (14.5, 15.6) | 6.7 (6.4, 7.1) | 9.1 (8.6, 9.5) |
| Trend | ||||||
| Linear | β=−0.10, p<0.001 | β=−0.10, p<0.001 | β=−0.10, p<0.001 | β=−0.11, p<0.001 | β=−0.10, p<0.001 | β=−0.08, p=0.002 |
| Quadratic | β<0.01, p<0.001 | β=0.00, p<0.001 | β=0.01, p<0.001 | β=0.01, p<0.001 | β=0.01, p<0.001 | β=0.00, p=0.039 |
Note. Repeated Lifetime Use = Used ≥3 times during lifetime; Current Use = Any past 30-day use; Repeated Past 30-Day Use = Used ≥3 times in the past 30 days; Frequent Use = Used ≥20 times in the past 30 days; Early use = Any use before age 13.