| Year | Rank | Number |
| 2011 | 5462 | 25 |
| 2010 | 7131 | 18 |
| 2009 | 5012 | 29 |
| 2008 | 6073 | 23 |
| 2007 | 4534 | 33 |
| 2006 | 5651 | 24 |
| 2005 | 5208 | 25 |
| 2004 | 4905 | 27 |
| 2003 | 3851 | 36 |
| 2002 | 4148 | 31 |
| 2001 | 4413 | 28 |
| 2000 | 4259 | 29 |
| 1999 | 3862 | 31 |
| 1998 | 3336 | 37 |
| 1997 | 3281 | 36 |
| 1996 | 4838 | 21 |
| 1995 | 7937 | 11 |
| 1994 | 8630 | 10 |
| 1992 | 11396 | 7 |
| 1991 | 14825 | 5 |