| Year | Count |
|---|---|
| 1974 | 10 |
| 1975 | 20 |
| 1978 | 14 |
| 1980 | 7 |
| 1981 | 11 |
| 1983 | 6 |
| 1985 | 11 |
| 1986 | 10 |
| 1987 | 10 |
| 1988 | 10 |
| 1989 | 24 |
| 1990 | 38 |
| 1991 | 22 |
| 1992 | 32 |
| 1993 | 82 |
| 1994 | 76 |
| 1995 | 64 |
| 1996 | 52 |
| 1997 | 60 |
| 1998 | 10 |
| 1999 | 18 |
| 2000 | 16 |
| 2001 | 12 |
| 2002 | 10 |
| 2004 | 15 |
| 2005 | 31 |
| 2006 | 39 |
| 2007 | 17 |
| 2008 | 61 |
| 2009 | 17 |
| 2010 | 14 |
| 2011 | 27 |
| 2012 | 12 |
| 2017 | 10 |
| 2019 | 10 |