| Year | Rank | Number |
| 2011 | 9134 | 12 |
| 2010 | 5773 | 23 |
| 2009 | 4907 | 29 |
| 2008 | 3997 | 39 |
| 2007 | 3375 | 49 |
| 2006 | 3504 | 45 |
| 2005 | 3363 | 45 |
| 2004 | 3988 | 35 |
| 2003 | 3134 | 47 |
| 2002 | 2775 | 54 |
| 2001 | 2701 | 55 |
| 2000 | 2854 | 50 |
| 1999 | 3049 | 43 |
| 1998 | 3492 | 34 |
| 1997 | 5430 | 18 |
| 1996 | 4457 | 23 |
| 1995 | 5975 | 15 |
| 1994 | 8163 | 10 |
| 1993 | 5428 | 17 |
| 1992 | 5277 | 18 |
| 1991 | 4333 | 23 |
| 1990 | 5563 | 16 |
| 1989 | 8072 | 9 |
| 1988 | 6290 | 12 |
| 1984 | 10478 | 5 |