| Year | Rank | Number |
| 2011 | 698 | 396 |
| 2010 | 856 | 313 |
| 2009 | 864 | 318 |
| 2008 | 873 | 318 |
| 2007 | 972 | 276 |
| 2006 | 1064 | 239 |
| 2005 | 1273 | 176 |
| 2004 | 1341 | 159 |
| 2003 | 1359 | 149 |
| 2002 | 1813 | 99 |
| 2001 | 1930 | 90 |
| 2000 | 1835 | 94 |
| 1999 | 2118 | 72 |
| 1998 | 2479 | 56 |
| 1997 | 3404 | 34 |
| 1996 | 5422 | 18 |
| 1995 | 6862 | 13 |
| 1994 | 5374 | 18 |
| 1993 | 7817 | 11 |
| 1992 | 14543 | 5 |
| 1991 | 7214 | 12 |
| 1990 | 10876 | 7 |
| 1989 | 10352 | 7 |
| 1987 | 10623 | 6 |
| 1985 | 7976 | 8 |