| Year | Rank | Number |
| 2011 | 18506 | 5 |
| 2010 | 18845 | 5 |
| 2008 | 13355 | 8 |
| 2006 | 13160 | 8 |
| 2005 | 11505 | 9 |
| 2004 | 9667 | 11 |
| 2002 | 17204 | 5 |
| 2001 | 17026 | 5 |
| 2000 | 7869 | 13 |
| 1999 | 9243 | 10 |
| 1998 | 10774 | 8 |
| 1997 | 6386 | 15 |
| 1996 | 12887 | 6 |
| 1995 | 12787 | 6 |
| 1994 | 14904 | 5 |
| 1993 | 7328 | 12 |
| 1992 | 9226 | 9 |
| 1991 | 11057 | 7 |
| 1990 | 14409 | 5 |