| Year | Count |
|---|---|
| 1952 | 5 |
| 1953 | 15 |
| 1955 | 21 |
| 1956 | 10 |
| 1957 | 48 |
| 1958 | 36 |
| 1959 | 25 |
| 1960 | 72 |
| 1961 | 47 |
| 1962 | 27 |
| 1963 | 13 |
| 1964 | 39 |
| 1965 | 36 |
| 1966 | 12 |
| 1967 | 12 |
| 1968 | 30 |
| 1969 | 57 |
| 1970 | 34 |
| 1971 | 52 |
| 1972 | 21 |
| 1973 | 65 |
| 1974 | 42 |
| 1975 | 44 |
| 1976 | 80 |
| 1977 | 113 |
| 1978 | 121 |
| 1979 | 127 |
| 1980 | 139 |
| 1981 | 122 |
| 1982 | 129 |
| 1983 | 148 |
| 1984 | 149 |
| 1985 | 192 |
| 1986 | 166 |
| 1987 | 167 |
| 1988 | 144 |
| 1989 | 87 |
| 1990 | 15 |
| 1991 | 30 |
| 1992 | 38 |
| 1993 | 45 |
| 1994 | 46 |
| 1995 | 8 |
| 1996 | 15 |
| 1997 | 5 |
| 1998 | 12 |
| 1999 | 17 |
| 2001 | 22 |
| 2002 | 5 |
| 2004 | 12 |
| 2011 | 10 |
| 2015 | 15 |