| Year | Rank | Number |
| 2011 | 4224 | 34 |
| 2010 | 6912 | 18 |
| 2009 | 4088 | 37 |
| 2008 | 4004 | 39 |
| 2007 | 4682 | 31 |
| 2006 | 3926 | 38 |
| 2005 | 3586 | 41 |
| 2004 | 3130 | 49 |
| 2003 | 2705 | 58 |
| 2002 | 4915 | 24 |
| 2001 | 8246 | 12 |
| 2000 | 5327 | 21 |
| 1999 | 5440 | 19 |
| 1998 | 6400 | 15 |
| 1997 | 6197 | 15 |
| 1996 | 7172 | 12 |
| 1995 | 4859 | 20 |
| 1994 | 4852 | 20 |
| 1993 | 7069 | 12 |
| 1992 | 11865 | 6 |
| 1991 | 13330 | 5 |
| 1989 | 12529 | 5 |