| Year | Rank | Number |
| 2010 | 17915 | 5 |
| 2005 | 11210 | 9 |
| 2004 | 17044 | 5 |
| 2003 | 12895 | 7 |
| 2002 | 14211 | 6 |
| 2001 | 10392 | 9 |
| 1999 | 9031 | 10 |
| 1998 | 6833 | 14 |
| 1997 | 6997 | 13 |
| 1996 | 10988 | 7 |
| 1995 | 12320 | 6 |
| 1993 | 10982 | 7 |
| 1991 | 9647 | 8 |
| 1990 | 11898 | 6 |
| 1989 | 13088 | 5 |
| 1988 | 7926 | 9 |
| 1986 | 11542 | 5 |
| 1985 | 8643 | 7 |
| 1982 | 11062 | 5 |
| 1981 | 8406 | 7 |