| Year | Rank | Number |
| 2011 | 18233 | 5 |
| 2010 | 12898 | 8 |
| 2009 | 13030 | 8 |
| 2008 | 12106 | 9 |
| 2007 | 13331 | 8 |
| 2005 | 13800 | 7 |
| 2004 | 6640 | 18 |
| 2003 | 13210 | 7 |
| 2002 | 8071 | 13 |
| 2001 | 8495 | 12 |
| 2000 | 11312 | 8 |
| 1999 | 9957 | 9 |
| 1998 | 6911 | 14 |
| 1997 | 13003 | 6 |
| 1996 | 11243 | 7 |
| 1994 | 8493 | 10 |
| 1993 | 6449 | 14 |
| 1992 | 11129 | 7 |
| 1991 | 12350 | 6 |
| 1986 | 11886 | 5 |
| 1973 | 7922 | 6 |