| Year | Count |
|---|---|
| 1948 | 11 |
| 1949 | 15 |
| 1950 | 28 |
| 1951 | 41 |
| 1952 | 74 |
| 1953 | 66 |
| 1954 | 68 |
| 1955 | 95 |
| 1956 | 107 |
| 1957 | 224 |
| 1958 | 232 |
| 1959 | 326 |
| 1960 | 298 |
| 1961 | 336 |
| 1963 | 113 |
| 1964 | 89 |
| 1965 | 79 |
| 1966 | 84 |
| 1967 | 84 |
| 1968 | 71 |
| 1969 | 57 |
| 1970 | 59 |
| 1971 | 43 |
| 1972 | 43 |
| 1973 | 32 |
| 1974 | 17 |
| 1975 | 23 |
| 1976 | 15 |
| 1977 | 46 |
| 1978 | 28 |
| 1979 | 38 |
| 1980 | 32 |
| 1981 | 16 |
| 1982 | 8 |
| 1983 | 15 |
| 1984 | 18 |
| 1985 | 7 |
| 1986 | 10 |
| 1987 | 8 |
| 1988 | 6 |
| 1989 | 9 |
| 1990 | 8 |
| 1991 | 7 |
| 1992 | 14 |
| 1993 | 6 |
| 1994 | 6 |