| Year | Count |
|---|---|
| 1974 | 10 |
| 1976 | 14 |
| 1977 | 19 |
| 1978 | 16 |
| 1979 | 5 |
| 1980 | 31 |
| 1981 | 33 |
| 1982 | 24 |
| 1983 | 33 |
| 1984 | 34 |
| 1985 | 18 |
| 1986 | 16 |
| 1987 | 64 |
| 1988 | 28 |
| 1989 | 33 |
| 1990 | 29 |
| 1991 | 48 |
| 1992 | 78 |
| 1993 | 40 |
| 1994 | 28 |
| 1995 | 40 |
| 1996 | 77 |
| 1997 | 85 |
| 1998 | 73 |
| 1999 | 43 |
| 2000 | 49 |
| 2001 | 23 |
| 2002 | 5 |
| 2003 | 10 |
| 2004 | 41 |
| 2005 | 12 |
| 2006 | 13 |
| 2007 | 5 |
| 2008 | 7 |
| 2010 | 12 |
| 2011 | 6 |
| 2016 | 8 |