| Year | Rank | Number |
| 2011 | 650 | 435 |
| 2010 | 655 | 445 |
| 2009 | 621 | 481 |
| 2008 | 819 | 348 |
| 2007 | 884 | 314 |
| 2006 | 972 | 268 |
| 2005 | 1081 | 219 |
| 2004 | 1067 | 216 |
| 2003 | 1593 | 121 |
| 2002 | 1329 | 146 |
| 2001 | 1459 | 129 |
| 2000 | 1523 | 119 |
| 1999 | 1719 | 94 |
| 1998 | 2049 | 72 |
| 1997 | 2390 | 55 |
| 1996 | 2850 | 42 |
| 1995 | 3032 | 38 |
| 1994 | 3621 | 30 |
| 1993 | 4402 | 23 |
| 1992 | 7115 | 12 |
| 1991 | 4513 | 22 |
| 1990 | 6164 | 14 |
| 1989 | 9798 | 7 |
| 1988 | 7763 | 9 |
| 1987 | 7428 | 9 |
| 1986 | 9689 | 6 |
| 1984 | 9256 | 6 |
| 1982 | 10657 | 5 |