| Year | Rank | Number |
| 2008 | 11487 | 6 |
| 2006 | 9893 | 7 |
| 2005 | 9429 | 7 |
| 2004 | 7731 | 9 |
| 2002 | 7879 | 8 |
| 2000 | 7681 | 8 |
| 1998 | 8836 | 6 |
| 1997 | 7548 | 7 |
| 1996 | 4979 | 12 |
| 1995 | 8132 | 6 |
| 1994 | 6013 | 9 |
| 1993 | 5123 | 11 |
| 1992 | 6319 | 8 |
| 1991 | 6772 | 7 |
| 1990 | 6019 | 8 |
| 1989 | 3873 | 14 |
| 1988 | 3985 | 12 |
| 1987 | 5684 | 7 |
| 1986 | 6192 | 6 |
| 1985 | 4145 | 10 |
| 1984 | 5817 | 6 |
| 1983 | 6590 | 5 |
| 1982 | 4341 | 9 |
| 1981 | 6595 | 5 |
| 1980 | 4253 | 9 |
| 1978 | 6118 | 5 |
| 1971 | 5178 | 5 |
| 1969 | 4620 | 5 |