| Year | Count |
|---|---|
| 1974 | 5 |
| 1987 | 26 |
| 1988 | 56 |
| 1989 | 31 |
| 1990 | 13 |
| 1991 | 18 |
| 1992 | 74 |
| 1993 | 23 |
| 1994 | 71 |
| 1995 | 59 |
| 1996 | 54 |
| 1997 | 69 |
| 1998 | 72 |
| 1999 | 67 |
| 2000 | 85 |
| 2001 | 45 |
| 2002 | 123 |
| 2003 | 103 |
| 2004 | 111 |
| 2005 | 72 |
| 2006 | 147 |
| 2007 | 68 |
| 2008 | 291 |
| 2009 | 189 |
| 2010 | 121 |
| 2011 | 106 |
| 2012 | 115 |
| 2013 | 92 |
| 2014 | 30 |
| 2015 | 10 |
| 2016 | 5 |
| 2017 | 6 |
| 2018 | 10 |
| 2024 | 6 |