| Year | Rank | Number |
| 2010 | 12814 | 8 |
| 2009 | 10218 | 11 |
| 2008 | 11154 | 10 |
| 2007 | 9813 | 12 |
| 2006 | 10210 | 11 |
| 2005 | 13686 | 7 |
| 2004 | 13415 | 7 |
| 2003 | 10011 | 10 |
| 2002 | 16729 | 5 |
| 2001 | 9033 | 11 |
| 2000 | 8267 | 12 |
| 1999 | 9879 | 9 |
| 1998 | 10586 | 8 |
| 1997 | 10254 | 8 |
| 1996 | 12582 | 6 |
| 1995 | 9102 | 9 |
| 1994 | 9173 | 9 |
| 1993 | 7245 | 12 |
| 1992 | 9074 | 9 |
| 1991 | 7653 | 11 |
| 1990 | 7065 | 12 |
| 1989 | 8349 | 9 |
| 1988 | 7387 | 10 |
| 1984 | 9653 | 6 |
| 1983 | 7597 | 8 |
| 1981 | 7705 | 8 |