| Sex and Year | Total* | 8th grade1 | 10th grade1 | 12th grade2 |
|---|---|---|---|---|
| Both Sexes | ||||
| 2003 | 14.9 | 6.7 | 18.2 | 30.9 |
| 2002 | 14.7 | 6.7 | 18.3 | 30.3 |
| 2001 | 16.6 | 7.7 | 21.9 | 32.7 |
| 2000 | 17.4 | 8.3 | 23.5 | 32.3 |
| 1999 | 17.7 | 9.4 | 22.5 | 32.9 |
| 1998 | 16.6 | 8.4 | 21.1 | 32.9 |
| 1997 | 17.4 | 8.2 | 22.4 | 34.2 |
| 1996 | 17.2 | 9.6 | 21.3 | 31.3 |
| 1995 | 17.0 | 8.3 | 20.8 | 33.2 |
| 1994 | 16.6 | 8.7 | 20.3 | 30.8 |
| 1993 | 15.4 | 7.8 | 19.8 | 28.9 |
| 1992 | 14.6 | 7.5 | 18.1 | 29.9 |
| 1991 | 16.1 | 7.6 | 20.5 | 31.6 |
| Male | ||||
| 2003 | 15.5 | 6.6 | 18.8 | 34.9 |
| 2002 | 15.6 | 7.1 | 19.3 | 34.3 |
| 2001 | 18.0 | 7.8 | 24.2 | 37.0 |
| 2000 | 19.1 | 8.2 | 26.2 | 38.4 |
| 1999 | 19.8 | 10.2 | 25.4 | 37.9 |
| 1998 | 17.8 | 8.5 | 22.3 | 39.0 |
| 1997 | 19.0 | 8.4 | 24.6 | 39.2 |
| 1996 | 18.4 | 9.7 | 23.0 | 35.4 |
| 1995 | 18.0 | 8.2 | 21.9 | 37.8 |
| 1994 | 18.4 | 9.0 | 23.2 | 34.5 |
| 1993 | 16.9 | 7.8 | 21.4 | 34.5 |
| 1992 | 15.3 | 7.4 | 18.6 | 35.2 |
| 1991 | 17.9 | 8.4 | 22.3 | 37.1 |
| Female | ||||
| 2003 | 14.1 | 6.8 | 17.7 | 26.9 |
| 2002 | 13.8 | 6.3 | 17.4 | 26.9 |
| 2001 | 15.1 | 7.4 | 19.7 | 28.4 |
| 2000 | 15.6 | 8.1 | 20.9 | 26.7 |
| 1999 | 15.6 | 8.6 | 19.8 | 27.7 |
| 1998 | 15.3 | 8.2 | 19.9 | 26.6 |
| 1997 | 15.7 | 7.9 | 20.2 | 29.1 |
| 1996 | 16.0 | 9.5 | 19.8 | 27.3 |
| 1995 | 16.0 | 8.2 | 19.6 | 28.8 |
| 1994 | 14.8 | 8.3 | 17.2 | 26.8 |
| 1993 | 14.0 | 7.8 | 18.1 | 23.5 |
| 1992 | 13.8 | 7.6 | 17.5 | 24.5 |
| 1991 | 14.2 | 7.0 | 18.7 | 25.4 |
* Estimates for 8th–12th grades combined are calculated by AEDS using the MTF public-use data.
1 The question was asked of only about half the 8th and 10th grade sample for 1991–1996. It was asked of the full sample for 1997–2003.
2 The question was asked of about one third of the 12th grade sample for 1991–2003.
NOTE: Standard errors are not available.
SOURCE: Johnston et al. (2004).