| Year | Rank | Number |
| 2008 | 16921 | 6 |
| 2007 | 17056 | 6 |
| 2006 | 16605 | 6 |
| 2002 | 13273 | 7 |
| 2001 | 17265 | 5 |
| 1996 | 15229 | 5 |
| 1995 | 12934 | 6 |
| 1993 | 15128 | 5 |
| 1990 | 11048 | 7 |
| 1989 | 11917 | 6 |
| 1988 | 8982 | 8 |
| 1987 | 9508 | 7 |
| 1986 | 7558 | 9 |
| 1985 | 7380 | 9 |
| 1984 | 6157 | 11 |
| 1983 | 4410 | 17 |
| 1982 | 6712 | 10 |
| 1981 | 6669 | 10 |
| 1980 | 3688 | 22 |
| 1979 | 4551 | 16 |
| 1978 | 5853 | 11 |
| 1977 | 5128 | 13 |
| 1976 | 4526 | 14 |
| 1975 | 5074 | 12 |
| 1974 | 6098 | 9 |
| 1973 | 6483 | 8 |
| 1972 | 5800 | 9 |