| Year | Count |
|---|---|
| 1973 | 10 |
| 1974 | 6 |
| 1975 | 5 |
| 1976 | 15 |
| 1978 | 6 |
| 1979 | 15 |
| 1981 | 13 |
| 1982 | 5 |
| 1983 | 10 |
| 1984 | 5 |
| 1985 | 6 |
| 1987 | 19 |
| 1988 | 7 |
| 1989 | 28 |
| 1990 | 7 |
| 1991 | 9 |
| 1992 | 46 |
| 1993 | 22 |
| 1994 | 39 |
| 1995 | 27 |
| 1996 | 38 |
| 1997 | 18 |
| 1998 | 43 |
| 1999 | 41 |
| 2000 | 56 |
| 2001 | 92 |
| 2002 | 68 |
| 2003 | 64 |
| 2004 | 123 |
| 2005 | 76 |
| 2006 | 86 |
| 2007 | 56 |
| 2008 | 91 |
| 2009 | 42 |
| 2010 | 29 |
| 2011 | 54 |
| 2012 | 10 |
| 2013 | 31 |
| 2014 | 5 |
| 2015 | 27 |
| 2016 | 14 |
| 2017 | 5 |
| 2019 | 5 |
| 2023 | 5 |