| Year | Enrolled | Not Enrolled |
|---|---|---|
| 2005 | 25.4 | 47.9 |
| 2004 | 25.6 | 50.5 |
| 2003 | 26.3 | 48.8 |
| 2002 | 26.0 | 47.8 |
| 2001 | 25.3 | 48.1 |
| 2000 | 23.9 | 46.5 |
| 1999 | 24.4 | 45.3 |
| 1998 | 27.0 | 52.4 |
| 1997 | 27.0 | 54.0 |
| 1996 | 24.5 | 47.8 |
| 1995 | 27.1 | 48.9 |
| 1994 | 27.8 | 50.9 |
| 1993 | 24.9 | 50.9 |
| 1992 | 23.3 | 47.5 |
| 1991 | 30.3 | 51.3 |