| Year | Count |
|---|---|
| 1948 | 6 |
| 1953 | 6 |
| 1956 | 5 |
| 1957 | 6 |
| 1958 | 23 |
| 1959 | 41 |
| 1960 | 47 |
| 1961 | 76 |
| 1962 | 43 |
| 1963 | 78 |
| 1964 | 81 |
| 1965 | 91 |
| 1966 | 50 |
| 1967 | 78 |
| 1968 | 83 |
| 1969 | 85 |
| 1970 | 65 |
| 1971 | 66 |
| 1972 | 43 |
| 1973 | 38 |
| 1974 | 49 |
| 1975 | 41 |
| 1976 | 27 |
| 1977 | 57 |
| 1978 | 51 |
| 1979 | 46 |
| 1980 | 33 |
| 1981 | 35 |
| 1982 | 28 |
| 1983 | 21 |
| 1984 | 23 |
| 1985 | 26 |
| 1986 | 14 |
| 1987 | 25 |
| 1988 | 22 |
| 1989 | 7 |
| 1990 | 8 |
| 1991 | 7 |
| 1995 | 5 |
| 1997 | 5 |