| Male | Female | Group Total | |||
|---|---|---|---|---|---|
| Mean | Mean | Mean | |||
| Year of Crash | 1991 | 32.3 | 34.0 | 32.8 | |
| 1992 | 33.3 | 35.4 | 33.9 | ||
| 1993 | 33.2 | 35.1 | 33.7 | ||
| 1994 | 33.8 | 37.3 | 34.9 | ||
| 1995 | 34.4 | 35.8 | 34.8 | ||
| 1996 | 36.0 | 37.4 | 36.4 | ||
| 1997 | 35.6 | 38.0 | 36.4 | ||
| 1998 | 35.3 | 37.6 | 36.0 | ||
| 1999 | 35.2 | 37.1 | 35.8 | ||
| 2000 | 35.5 | 37.8 | 36.2 | ||
| 2001 | 35.7 | 36.5 | 36.0 | ||
| 2002 | 35.6 | 37.2 | 36.0 | ||
| 2003 | 35.8 | 37.2 | 36.2 | ||
| 2004 | 35.8 | 36.7 | 36.1 | ||
| Group Total | 34.8 | 36.6 | 35.3 | ||