| Year | Rank | Number |
| 2011 | 3531 | 30 |
| 2010 | 3336 | 33 |
| 2009 | 4060 | 25 |
| 2008 | 5158 | 18 |
| 2007 | 3337 | 33 |
| 2006 | 3414 | 31 |
| 2005 | 4380 | 20 |
| 2004 | 4338 | 20 |
| 2003 | 4193 | 20 |
| 2002 | 4801 | 16 |
| 2001 | 4034 | 20 |
| 2000 | 5738 | 12 |
| 1999 | 4237 | 17 |
| 1998 | 4106 | 17 |
| 1997 | 4567 | 14 |
| 1996 | 4747 | 13 |
| 1995 | 5315 | 11 |
| 1994 | 6090 | 9 |
| 1993 | 6524 | 8 |
| 1992 | 9100 | 5 |
| 1991 | 7745 | 6 |