| Year | Rank | Number |
| 2006 | 16009 | 6 |
| 2005 | 12340 | 8 |
| 2004 | 17296 | 5 |
| 2003 | 13043 | 7 |
| 2002 | 9115 | 11 |
| 2001 | 7496 | 14 |
| 1999 | 6645 | 15 |
| 1998 | 5677 | 18 |
| 1997 | 6311 | 15 |
| 1996 | 5384 | 18 |
| 1995 | 4407 | 23 |
| 1994 | 4592 | 22 |
| 1993 | 7750 | 11 |
| 1992 | 5361 | 18 |
| 1991 | 8240 | 10 |
| 1990 | 7055 | 12 |
| 1989 | 7187 | 11 |
| 1988 | 7983 | 9 |
| 1987 | 10423 | 6 |