| Year | Count |
|---|---|
| 1961 | 5 |
| 1962 | 5 |
| 1964 | 9 |
| 1965 | 8 |
| 1966 | 23 |
| 1967 | 19 |
| 1968 | 30 |
| 1969 | 28 |
| 1970 | 66 |
| 1971 | 101 |
| 1972 | 111 |
| 1973 | 143 |
| 1974 | 157 |
| 1975 | 172 |
| 1976 | 144 |
| 1977 | 239 |
| 1978 | 243 |
| 1979 | 178 |
| 1980 | 229 |
| 1981 | 289 |
| 1982 | 265 |
| 1983 | 295 |
| 1984 | 162 |
| 1985 | 209 |
| 1986 | 280 |
| 1987 | 182 |
| 1988 | 97 |
| 1989 | 182 |
| 1989 | 5 |
| 1990 | 183 |
| 1991 | 268 |
| 1992 | 233 |
| 1993 | 349 |
| 1994 | 202 |
| 1995 | 167 |
| 1996 | 231 |
| 1997 | 212 |
| 1998 | 226 |
| 1999 | 87 |
| 2000 | 98 |
| 2001 | 71 |
| 2002 | 35 |
| 2003 | 22 |
| 2004 | 22 |
| 2005 | 38 |
| 2006 | 18 |
| 2008 | 10 |
| 2010 | 5 |
| 2014 | 5 |
| 2022 | 5 |