| Year | Rank | Number |
| 2011 | 11383 | 6 |
| 2010 | 13121 | 5 |
| 2008 | 13405 | 5 |
| 2005 | 10671 | 6 |
| 2003 | 11701 | 5 |
| 2001 | 8693 | 7 |
| 2000 | 9613 | 6 |
| 1999 | 8242 | 7 |
| 1998 | 6527 | 9 |
| 1997 | 9935 | 5 |
| 1996 | 6764 | 8 |
| 1995 | 7325 | 7 |
| 1994 | 5245 | 11 |
| 1993 | 4112 | 15 |
| 1992 | 7880 | 6 |
| 1991 | 7690 | 6 |
| 1990 | 7544 | 6 |
| 1989 | 4976 | 10 |
| 1988 | 4583 | 10 |
| 1983 | 5805 | 6 |
| 1982 | 4382 | 9 |
| 1981 | 5814 | 6 |
| 1980 | 5182 | 7 |
| 1979 | 6475 | 5 |