| Year | Count |
|---|---|
| 1966 | 5 |
| 1969 | 6 |
| 1971 | 33 |
| 1972 | 42 |
| 1973 | 81 |
| 1974 | 133 |
| 1975 | 107 |
| 1976 | 203 |
| 1977 | 307 |
| 1978 | 324 |
| 1979 | 183 |
| 1980 | 156 |
| 1981 | 205 |
| 1982 | 234 |
| 1983 | 190 |
| 1984 | 161 |
| 1985 | 202 |
| 1986 | 234 |
| 1987 | 311 |
| 1988 | 272 |
| 1989 | 260 |
| 1990 | 256 |
| 1991 | 259 |
| 1992 | 268 |
| 1993 | 286 |
| 1994 | 260 |
| 1995 | 158 |
| 1996 | 174 |
| 1997 | 149 |
| 1998 | 109 |
| 1999 | 118 |
| 2000 | 141 |
| 2001 | 129 |
| 2002 | 87 |
| 2003 | 66 |
| 2004 | 87 |
| 2005 | 45 |
| 2006 | 84 |
| 2007 | 63 |
| 2008 | 129 |
| 2009 | 29 |
| 2010 | 41 |
| 2011 | 68 |
| 2012 | 38 |
| 2013 | 12 |
| 2014 | 22 |
| 2015 | 12 |
| 2016 | 38 |
| 2017 | 23 |
| 2018 | 10 |
| 2020 | 19 |
| 2021 | 6 |
| 2022 | 15 |