| Year | Count |
|---|---|
| 1987 | 22 |
| 1988 | 41 |
| 1989 | 68 |
| 1990 | 70 |
| 1991 | 101 |
| 1992 | 137 |
| 1993 | 158 |
| 1994 | 99 |
| 1995 | 90 |
| 1996 | 65 |
| 1997 | 85 |
| 1998 | 99 |
| 1999 | 33 |
| 2000 | 58 |
| 2001 | 59 |
| 2002 | 113 |
| 2003 | 49 |
| 2004 | 72 |
| 2005 | 48 |
| 2006 | 97 |
| 2007 | 127 |
| 2008 | 68 |
| 2009 | 58 |
| 2010 | 78 |
| 2011 | 91 |
| 2012 | 35 |
| 2013 | 24 |
| 2014 | 5 |
| 2015 | 22 |
| 2016 | 10 |
| 2017 | 7 |
| 2018 | 10 |
| 2022 | 5 |