| Year | Rank | Number |
| 2011 | 8691 | 13 |
| 2010 | 11464 | 9 |
| 2009 | 10787 | 10 |
| 2008 | 7129 | 18 |
| 2007 | 6375 | 21 |
| 2006 | 8358 | 14 |
| 2005 | 8452 | 13 |
| 2004 | 7490 | 15 |
| 2003 | 7686 | 14 |
| 2002 | 5499 | 21 |
| 2001 | 8325 | 12 |
| 2000 | 9342 | 10 |
| 1999 | 6916 | 14 |
| 1998 | 7674 | 12 |
| 1997 | 7909 | 11 |
| 1996 | 9826 | 8 |
| 1995 | 14037 | 5 |
| 1994 | 7220 | 12 |
| 1993 | 14074 | 5 |
| 1992 | 8931 | 9 |
| 1991 | 8133 | 10 |
| 1984 | 10815 | 5 |