| Year | Count |
|---|---|
| 1972 | 6 |
| 1973 | 7 |
| 1977 | 5 |
| 1978 | 5 |
| 1979 | 11 |
| 1980 | 5 |
| 1981 | 26 |
| 1983 | 5 |
| 1985 | 6 |
| 1987 | 12 |
| 1989 | 13 |
| 1990 | 5 |
| 1994 | 7 |
| 1996 | 12 |
| 1997 | 174 |
| 1998 | 300 |
| 1999 | 102 |
| 2000 | 57 |
| 2001 | 58 |
| 2002 | 43 |
| 2003 | 20 |
| 2004 | 22 |
| 2005 | 65 |
| 2006 | 36 |
| 2007 | 12 |
| 2008 | 45 |
| 2009 | 7 |
| 2010 | 7 |
| 2011 | 12 |
| 2012 | 10 |
| 2013 | 12 |
| 2024 | 5 |