| Year | Count |
|---|---|
| 1969 | 50 |
| 1970 | 57 |
| 1971 | 88 |
| 1972 | 160 |
| 1973 | 131 |
| 1974 | 127 |
| 1975 | 119 |
| 1976 | 113 |
| 1977 | 110 |
| 1978 | 139 |
| 1979 | 118 |
| 1980 | 129 |
| 1981 | 108 |
| 1982 | 101 |
| 1983 | 140 |
| 1984 | 58 |
| 1985 | 128 |
| 1986 | 100 |
| 1987 | 208 |
| 1988 | 154 |
| 1989 | 160 |
| 1990 | 217 |
| 1991 | 194 |
| 1992 | 162 |
| 1993 | 213 |
| 1994 | 171 |
| 1995 | 97 |
| 1996 | 109 |
| 1997 | 126 |
| 1998 | 115 |
| 1999 | 62 |
| 2000 | 54 |
| 2001 | 63 |
| 2002 | 47 |
| 2003 | 46 |
| 2004 | 51 |
| 2005 | 63 |
| 2006 | 50 |
| 2007 | 25 |
| 2008 | 21 |
| 2009 | 16 |
| 2011 | 16 |
| 2012 | 34 |
| 2013 | 33 |
| 2014 | 15 |
| 2015 | 10 |
| 2016 | 19 |
| 2017 | 10 |
| 2020 | 5 |
| 2022 | 6 |