| Year | Count |
|---|---|
| 1952 | 5 |
| 1958 | 12 |
| 1959 | 22 |
| 1960 | 23 |
| 1962 | 8 |
| 1963 | 5 |
| 1964 | 5 |
| 1965 | 12 |
| 1966 | 26 |
| 1967 | 16 |
| 1968 | 22 |
| 1969 | 24 |
| 1970 | 42 |
| 1971 | 28 |
| 1972 | 35 |
| 1973 | 41 |
| 1974 | 21 |
| 1975 | 32 |
| 1976 | 26 |
| 1977 | 28 |
| 1978 | 43 |
| 1979 | 45 |
| 1980 | 40 |
| 1981 | 21 |
| 1982 | 12 |
| 1983 | 11 |
| 1984 | 9 |
| 1985 | 11 |
| 1986 | 14 |
| 1987 | 12 |
| 1988 | 5 |