| Year | Rank | Number |
| 2011 | 9464 | 12 |
| 2010 | 8133 | 15 |
| 2009 | 9142 | 13 |
| 2008 | 5872 | 24 |
| 2007 | 6007 | 23 |
| 2006 | 4749 | 30 |
| 2005 | 3916 | 37 |
| 2004 | 4891 | 27 |
| 2003 | 4377 | 30 |
| 2002 | 4140 | 31 |
| 2001 | 4527 | 27 |
| 2000 | 7031 | 15 |
| 1999 | 7550 | 13 |
| 1998 | 7864 | 12 |
| 1997 | 8797 | 10 |
| 1996 | 7435 | 12 |
| 1995 | 8524 | 10 |
| 1993 | 14955 | 5 |
| 1992 | 14715 | 5 |
| 1991 | 11073 | 7 |