| Year | Count |
|---|---|
| 1974 | 10 |
| 1978 | 6 |
| 1980 | 13 |
| 1981 | 12 |
| 1982 | 12 |
| 1983 | 12 |
| 1985 | 55 |
| 1986 | 7 |
| 1987 | 25 |
| 1988 | 21 |
| 1989 | 33 |
| 1990 | 42 |
| 1991 | 5 |
| 1992 | 10 |
| 1993 | 28 |
| 1994 | 39 |
| 1995 | 23 |
| 1996 | 32 |
| 1997 | 19 |
| 1998 | 23 |
| 1999 | 27 |
| 2000 | 42 |
| 2001 | 11 |
| 2002 | 7 |
| 2003 | 6 |
| 2005 | 11 |
| 2006 | 38 |
| 2007 | 7 |
| 2008 | 37 |
| 2009 | 30 |
| 2010 | 32 |
| 2011 | 5 |
| 2012 | 10 |
| 2013 | 12 |