| Year | Count |
|---|---|
| 1983 | 10 |
| 1984 | 36 |
| 1985 | 48 |
| 1986 | 54 |
| 1987 | 59 |
| 1988 | 114 |
| 1989 | 144 |
| 1990 | 292 |
| 1991 | 356 |
| 1992 | 588 |
| 1993 | 638 |
| 1994 | 582 |
| 1995 | 10 |
| 1995 | 560 |
| 1996 | 456 |
| 1997 | 411 |
| 1998 | 407 |
| 1999 | 390 |
| 2000 | 282 |
| 2001 | 309 |
| 2002 | 151 |
| 2003 | 181 |
| 2004 | 115 |
| 2005 | 128 |
| 2006 | 100 |
| 2007 | 49 |
| 2008 | 63 |
| 2009 | 29 |
| 2010 | 17 |
| 2011 | 10 |
| 2012 | 5 |
| 2013 | 7 |
| 2014 | 19 |
| 2015 | 10 |
| 2016 | 10 |