| Year | Rank | Number |
| 2007 | 12445 | 5 |
| 2005 | 10189 | 6 |
| 2002 | 10757 | 5 |
| 2000 | 10443 | 5 |
| 1999 | 7909 | 7 |
| 1997 | 8176 | 6 |
| 1996 | 6525 | 8 |
| 1995 | 4062 | 15 |
| 1994 | 5886 | 9 |
| 1993 | 5016 | 11 |
| 1992 | 6154 | 8 |
| 1991 | 4485 | 12 |
| 1990 | 3059 | 20 |
| 1989 | 2472 | 26 |
| 1988 | 2857 | 19 |
| 1987 | 2726 | 19 |
| 1986 | 2512 | 21 |
| 1985 | 3216 | 14 |
| 1984 | 3703 | 11 |
| 1983 | 3223 | 13 |
| 1982 | 2827 | 16 |
| 1981 | 4149 | 9 |
| 1980 | 3845 | 10 |
| 1978 | 4575 | 7 |
| 1977 | 4178 | 8 |
| 1975 | 3956 | 8 |
| 1974 | 2953 | 12 |
| 1973 | 5127 | 5 |
| 1970 | 4235 | 6 |