| Year | Rank | Number |
| 2011 | 9217 | 12 |
| 2010 | 8337 | 14 |
| 2009 | 8940 | 13 |
| 2008 | 8182 | 15 |
| 2007 | 6601 | 20 |
| 2006 | 8337 | 14 |
| 2005 | 6059 | 20 |
| 2004 | 7921 | 14 |
| 2003 | 6652 | 17 |
| 2002 | 11358 | 8 |
| 2001 | 8307 | 12 |
| 2000 | 7665 | 13 |
| 1999 | 7826 | 12 |
| 1998 | 12823 | 6 |
| 1997 | 11114 | 7 |
| 1995 | 9784 | 8 |
| 1994 | 13918 | 5 |
| 1993 | 12111 | 6 |
| 1992 | 10736 | 7 |
| 1991 | 11831 | 6 |
| 1984 | 10741 | 5 |
| 1979 | 10519 | 5 |