| Year | Count |
|---|---|
| 1969 | 6 |
| 1971 | 6 |
| 1972 | 12 |
| 1974 | 6 |
| 1975 | 25 |
| 1975 | 5 |
| 1976 | 16 |
| 1978 | 58 |
| 1979 | 115 |
| 1980 | 92 |
| 1981 | 59 |
| 1982 | 126 |
| 1983 | 59 |
| 1984 | 103 |
| 1985 | 170 |
| 1985 | 5 |
| 1986 | 178 |
| 1987 | 150 |
| 1987 | 6 |
| 1988 | 143 |
| 1988 | 5 |
| 1989 | 112 |
| 1990 | 201 |
| 1991 | 138 |
| 1992 | 142 |
| 1993 | 97 |
| 1993 | 10 |
| 1994 | 88 |
| 1995 | 114 |
| 1996 | 101 |
| 1997 | 27 |
| 1998 | 41 |
| 1999 | 31 |
| 2000 | 38 |
| 2001 | 5 |
| 2002 | 21 |
| 2003 | 49 |
| 2004 | 63 |
| 2005 | 75 |
| 2006 | 27 |
| 2007 | 21 |
| 2008 | 8 |
| 2010 | 15 |
| 2011 | 10 |
| 2012 | 5 |
| 2013 | 5 |
| 2016 | 14 |