| Year | Count |
|---|---|
| 1950 | 10 |
| 1952 | 10 |
| 1953 | 26 |
| 1954 | 6 |
| 1955 | 10 |
| 1956 | 12 |
| 1958 | 7 |
| 1960 | 10 |
| 1961 | 19 |
| 1963 | 10 |
| 1964 | 5 |
| 1965 | 18 |
| 1966 | 10 |
| 1967 | 22 |
| 1968 | 23 |
| 1969 | 31 |
| 1970 | 29 |
| 1971 | 75 |
| 1972 | 167 |
| 1973 | 220 |
| 1974 | 82 |
| 1975 | 50 |
| 1976 | 50 |
| 1977 | 47 |
| 1978 | 39 |
| 1979 | 12 |
| 1980 | 28 |
| 1981 | 44 |
| 1982 | 59 |
| 1983 | 59 |
| 1984 | 34 |
| 1985 | 41 |
| 1986 | 22 |
| 1987 | 20 |
| 1988 | 31 |
| 1989 | 188 |
| 1990 | 213 |
| 1991 | 103 |
| 1992 | 75 |
| 1993 | 58 |
| 1994 | 24 |
| 1995 | 24 |
| 1996 | 20 |
| 1997 | 19 |
| 1998 | 5 |
| 1999 | 29 |
| 2000 | 20 |
| 2002 | 5 |
| 2003 | 6 |
| 2004 | 12 |
| 2006 | 24 |
| 2008 | 19 |
| 2009 | 6 |
| 2011 | 16 |
| 2012 | 12 |
| 2017 | 6 |
| 2018 | 5 |
| 2020 | 10 |