| Year | Rank | Number |
| 2011 | 4460 | 32 |
| 2010 | 5006 | 28 |
| 2009 | 6337 | 21 |
| 2008 | 6403 | 21 |
| 2007 | 9188 | 13 |
| 2006 | 5132 | 27 |
| 2005 | 5665 | 22 |
| 2004 | 4533 | 30 |
| 2003 | 6154 | 19 |
| 2002 | 5970 | 19 |
| 2001 | 5668 | 20 |
| 2000 | 6605 | 16 |
| 1999 | 6625 | 15 |
| 1998 | 8849 | 10 |
| 1997 | 9329 | 9 |
| 1996 | 11014 | 7 |
| 1995 | 6077 | 15 |
| 1994 | 6828 | 13 |
| 1993 | 9005 | 9 |
| 1992 | 5826 | 16 |
| 1991 | 9675 | 8 |
| 1990 | 8111 | 10 |
| 1989 | 9053 | 8 |
| 1988 | 7943 | 9 |
| 1987 | 9149 | 7 |
| 1986 | 8880 | 7 |
| 1984 | 11021 | 5 |
| 1982 | 11106 | 5 |
| 1979 | 8354 | 7 |