| Year | Rank | Number |
| 2008 | 19433 | 5 |
| 2001 | 10711 | 9 |
| 1999 | 12225 | 7 |
| 1998 | 9046 | 10 |
| 1997 | 8150 | 11 |
| 1996 | 7001 | 13 |
| 1995 | 5864 | 16 |
| 1994 | 6943 | 13 |
| 1993 | 5847 | 16 |
| 1992 | 5407 | 18 |
| 1991 | 6149 | 15 |
| 1990 | 6032 | 15 |
| 1989 | 6805 | 12 |
| 1988 | 6134 | 13 |
| 1987 | 6192 | 12 |
| 1986 | 7519 | 9 |
| 1985 | 10167 | 6 |
| 1984 | 7183 | 9 |
| 1982 | 5417 | 13 |
| 1981 | 4459 | 17 |
| 1980 | 5768 | 12 |
| 1979 | 6018 | 11 |
| 1976 | 7039 | 8 |
| 1975 | 7659 | 7 |
| 1974 | 8342 | 6 |