| Year | Rank | Number |
| 2011 | 9103 | 12 |
| 2010 | 13466 | 7 |
| 2009 | 10603 | 10 |
| 2008 | 9479 | 12 |
| 2007 | 9528 | 12 |
| 2006 | 9900 | 11 |
| 2005 | 10143 | 10 |
| 2004 | 7395 | 15 |
| 2003 | 8526 | 12 |
| 2002 | 10272 | 9 |
| 2001 | 12105 | 7 |
| 2000 | 9175 | 10 |
| 1999 | 14469 | 5 |
| 1998 | 11166 | 7 |
| 1997 | 13792 | 5 |
| 1995 | 9583 | 8 |
| 1991 | 13197 | 5 |
| 1990 | 11427 | 6 |
| 1989 | 6537 | 12 |
| 1988 | 10398 | 6 |
| 1986 | 9562 | 6 |
| 1985 | 8330 | 7 |