| Year | Count |
|---|---|
| 1971 | 10 |
| 1972 | 12 |
| 1974 | 6 |
| 1976 | 12 |
| 1977 | 12 |
| 1979 | 10 |
| 1981 | 18 |
| 1982 | 16 |
| 1983 | 34 |
| 1985 | 18 |
| 1986 | 24 |
| 1987 | 21 |
| 1988 | 24 |
| 1989 | 32 |
| 1990 | 38 |
| 1991 | 55 |
| 1992 | 57 |
| 1993 | 24 |
| 1994 | 44 |
| 1995 | 36 |
| 1996 | 24 |
| 1997 | 47 |
| 1998 | 14 |
| 1999 | 45 |
| 2000 | 8 |
| 2001 | 70 |
| 2002 | 19 |
| 2003 | 10 |
| 2004 | 24 |
| 2005 | 10 |
| 2006 | 30 |
| 2008 | 15 |
| 2009 | 24 |
| 2010 | 6 |
| 2012 | 15 |
| 2016 | 10 |
| 2021 | 6 |