| Year | Rank | Number |
| 2011 | 1591 | 135 |
| 2010 | 1743 | 119 |
| 2009 | 1867 | 112 |
| 2008 | 1388 | 171 |
| 2007 | 1430 | 165 |
| 2006 | 2008 | 98 |
| 2005 | 2577 | 66 |
| 2004 | 2283 | 76 |
| 2003 | 2607 | 61 |
| 2002 | 2674 | 57 |
| 2001 | 3490 | 38 |
| 2000 | 3887 | 32 |
| 1999 | 4087 | 28 |
| 1998 | 4496 | 24 |
| 1997 | 4239 | 25 |
| 1996 | 4883 | 20 |
| 1995 | 5030 | 19 |
| 1994 | 7124 | 12 |
| 1993 | 8084 | 10 |
| 1992 | 5496 | 17 |
| 1991 | 5673 | 16 |
| 1990 | 8527 | 9 |
| 1988 | 5326 | 15 |
| 1987 | 9889 | 6 |
| 1984 | 10488 | 5 |