| Year | Rank | Number |
| 2011 | 8821 | 13 |
| 2010 | 6258 | 21 |
| 2009 | 6354 | 21 |
| 2008 | 7196 | 18 |
| 2007 | 6423 | 21 |
| 2006 | 10206 | 11 |
| 2005 | 6971 | 17 |
| 2004 | 6920 | 17 |
| 2003 | 6421 | 18 |
| 2002 | 4823 | 25 |
| 2001 | 5454 | 21 |
| 2000 | 8845 | 11 |
| 1999 | 9875 | 9 |
| 1998 | 10583 | 8 |
| 1997 | 9384 | 9 |
| 1996 | 14560 | 5 |
| 1995 | 11071 | 7 |
| 1994 | 14460 | 5 |
| 1992 | 14293 | 5 |
| 1991 | 14180 | 5 |