| Year | Count |
|---|---|
| 1968 | 11 |
| 1969 | 7 |
| 1970 | 20 |
| 1971 | 14 |
| 1972 | 23 |
| 1973 | 7 |
| 1975 | 15 |
| 1976 | 6 |
| 1977 | 12 |
| 1977 | 5 |
| 1978 | 66 |
| 1979 | 25 |
| 1979 | 10 |
| 1980 | 44 |
| 1980 | 15 |
| 1981 | 30 |
| 1982 | 18 |
| 1983 | 47 |
| 1984 | 50 |
| 1985 | 219 |
| 1985 | 19 |
| 1986 | 116 |
| 1987 | 92 |
| 1988 | 255 |
| 1989 | 99 |
| 1989 | 6 |
| 1990 | 126 |
| 1990 | 21 |
| 1991 | 157 |
| 1992 | 175 |
| 1992 | 11 |
| 1993 | 161 |
| 1993 | 6 |
| 1994 | 139 |
| 1995 | 81 |
| 1996 | 129 |
| 1996 | 5 |
| 1997 | 138 |
| 1998 | 115 |
| 1999 | 89 |
| 2000 | 57 |
| 2001 | 83 |
| 2002 | 40 |
| 2003 | 26 |
| 2004 | 100 |
| 2005 | 63 |
| 2006 | 21 |
| 2007 | 32 |
| 2008 | 93 |
| 2009 | 14 |
| 2010 | 53 |
| 2011 | 13 |
| 2012 | 21 |
| 2023 | 5 |