| Year | Count |
|---|---|
| 1965 | 15 |
| 1966 | 10 |
| 1968 | 5 |
| 1969 | 27 |
| 1970 | 49 |
| 1971 | 60 |
| 1972 | 74 |
| 1973 | 86 |
| 1974 | 106 |
| 1975 | 82 |
| 1976 | 116 |
| 1977 | 149 |
| 1978 | 114 |
| 1979 | 117 |
| 1980 | 128 |
| 1981 | 64 |
| 1982 | 77 |
| 1983 | 70 |
| 1984 | 74 |
| 1985 | 39 |
| 1986 | 66 |
| 1987 | 61 |
| 1988 | 62 |
| 1989 | 57 |
| 1990 | 93 |
| 1991 | 94 |
| 1992 | 74 |
| 1993 | 74 |
| 1994 | 71 |
| 1995 | 77 |
| 1996 | 84 |
| 1997 | 61 |
| 1998 | 50 |
| 1999 | 58 |
| 2000 | 60 |
| 2001 | 42 |
| 2002 | 36 |
| 2003 | 55 |
| 2004 | 41 |
| 2005 | 35 |
| 2006 | 33 |
| 2007 | 37 |
| 2008 | 52 |
| 2009 | 27 |
| 2010 | 28 |
| 2011 | 47 |
| 2012 | 12 |
| 2013 | 15 |
| 2014 | 19 |
| 2015 | 21 |
| 2016 | 18 |
| 2017 | 5 |
| 2019 | 16 |
| 2021 | 5 |
| 2022 | 5 |