| Year | Rank | Number |
| 2011 | 5441 | 25 |
| 2010 | 5711 | 24 |
| 2009 | 4848 | 30 |
| 2008 | 5373 | 27 |
| 2007 | 5815 | 24 |
| 2006 | 6734 | 19 |
| 2005 | 4321 | 32 |
| 2004 | 5319 | 24 |
| 2003 | 6473 | 18 |
| 2002 | 8632 | 12 |
| 2001 | 5985 | 19 |
| 2000 | 6123 | 18 |
| 1999 | 8589 | 11 |
| 1998 | 6959 | 14 |
| 1997 | 8139 | 11 |
| 1996 | 8594 | 10 |
| 1995 | 10174 | 8 |
| 1994 | 9325 | 9 |
| 1993 | 6491 | 14 |
| 1992 | 10111 | 8 |
| 1990 | 12339 | 6 |
| 1989 | 8485 | 9 |
| 1988 | 4590 | 19 |
| 1987 | 5493 | 14 |
| 1984 | 11499 | 5 |
| 1982 | 11594 | 5 |