| Year | Rank | Number |
| 2011 | 12448 | 8 |
| 2010 | 9952 | 11 |
| 2009 | 9490 | 12 |
| 2008 | 9112 | 13 |
| 2007 | 9142 | 13 |
| 2006 | 12732 | 8 |
| 2005 | 7232 | 16 |
| 2004 | 9434 | 11 |
| 2003 | 11641 | 8 |
| 2002 | 11438 | 8 |
| 2001 | 7868 | 13 |
| 2000 | 13690 | 6 |
| 1999 | 10654 | 8 |
| 1998 | 12946 | 6 |
| 1997 | 9266 | 9 |
| 1996 | 9858 | 8 |
| 1995 | 10873 | 7 |
| 1994 | 6799 | 13 |
| 1993 | 7664 | 11 |
| 1992 | 6104 | 15 |
| 1991 | 9609 | 8 |
| 1990 | 8063 | 10 |
| 1989 | 6272 | 13 |
| 1988 | 7898 | 9 |
| 1987 | 10247 | 6 |
| 1985 | 8603 | 7 |
| 1984 | 9469 | 6 |
| 1983 | 8291 | 7 |