| Year | Count |
|---|---|
| 1950 | 6 |
| 1951 | 9 |
| 1952 | 7 |
| 1953 | 14 |
| 1954 | 12 |
| 1955 | 11 |
| 1956 | 17 |
| 1957 | 48 |
| 1958 | 40 |
| 1959 | 38 |
| 1960 | 40 |
| 1961 | 36 |
| 1963 | 20 |
| 1964 | 22 |
| 1965 | 19 |
| 1966 | 10 |
| 1967 | 12 |
| 1968 | 5 |
| 1969 | 15 |
| 1970 | 10 |
| 1971 | 12 |
| 1972 | 5 |
| 1973 | 6 |
| 1974 | 11 |
| 1975 | 6 |
| 1976 | 8 |
| 1978 | 10 |
| 1979 | 18 |
| 1990 | 6 |
| 1991 | 5 |
| 1992 | 8 |
| 1993 | 5 |
| 1994 | 5 |
| 1995 | 5 |
| 1996 | 5 |
| 1997 | 5 |
| 1999 | 5 |