| Year/Approach | MIMIC |
| 1991 | 44.59% |
| 1992 | 43.27% |
| 1993 | 41.97% |
| 1994 | 41.71% |
| 1995 | 41.27% |
| 1996 | 41.10% |
| 1997 | 40.28% |
| 1998 | 41.81% |
| 1999 | 41.95% |
| 2000 | 40.81% |
| 2001 | 40.21% |
| 2002 | 40.62% |
| 2003 | 40.50% |
| 2004 | 39.20% |
| 2005 | 32.05% |
| 2006 | 31.61% |
| 2007 | 31.63% |
| Average | 39.68% |