| Year | Rank | Number |
| 2009 | 18833 | 5 |
| 2008 | 19204 | 5 |
| 2007 | 11270 | 10 |
| 2006 | 14446 | 7 |
| 2005 | 9182 | 12 |
| 2003 | 13243 | 7 |
| 2002 | 10713 | 9 |
| 2001 | 9099 | 11 |
| 1999 | 10954 | 8 |
| 1998 | 10696 | 8 |
| 1997 | 15099 | 5 |
| 1996 | 11277 | 7 |
| 1994 | 8512 | 10 |
| 1993 | 11254 | 7 |
| 1991 | 9858 | 8 |
| 1989 | 10353 | 7 |
| 1988 | 11158 | 6 |
| 1985 | 10037 | 6 |
| 1984 | 9809 | 6 |