| Year | Rank | Number |
| 2006 | 16508 | 6 |
| 2004 | 17976 | 5 |
| 2003 | 11042 | 9 |
| 2001 | 13038 | 7 |
| 2000 | 11467 | 8 |
| 1999 | 5831 | 18 |
| 1998 | 4892 | 22 |
| 1997 | 6398 | 15 |
| 1996 | 7010 | 13 |
| 1995 | 6508 | 14 |
| 1994 | 5170 | 19 |
| 1993 | 4482 | 23 |
| 1992 | 3747 | 29 |
| 1991 | 3136 | 36 |
| 1990 | 3483 | 31 |
| 1989 | 2555 | 45 |
| 1988 | 1978 | 61 |
| 1987 | 1786 | 66 |
| 1986 | 1583 | 76 |
| 1985 | 2067 | 52 |
| 1984 | 1382 | 85 |
| 1983 | 1362 | 88 |
| 1982 | 1708 | 66 |
| 1981 | 1927 | 56 |