| Year | Rank | Number |
| 2011 | 4583 | 21 |
| 2010 | 4057 | 25 |
| 2009 | 3861 | 27 |
| 2008 | 3703 | 29 |
| 2007 | 3852 | 27 |
| 2006 | 4448 | 21 |
| 2005 | 3896 | 24 |
| 2004 | 3509 | 27 |
| 2003 | 3490 | 26 |
| 2002 | 3996 | 21 |
| 2001 | 4408 | 18 |
| 2000 | 5796 | 12 |
| 1999 | 3788 | 20 |
| 1998 | 4133 | 17 |
| 1997 | 5537 | 11 |
| 1996 | 4794 | 13 |
| 1995 | 3796 | 17 |
| 1994 | 6186 | 9 |
| 1993 | 4164 | 15 |
| 1992 | 6498 | 8 |
| 1991 | 4988 | 11 |
| 1990 | 5259 | 10 |
| 1989 | 5454 | 9 |
| 1988 | 8118 | 5 |
| 1987 | 3658 | 13 |
| 1981 | 6940 | 5 |
| 1976 | 6182 | 5 |