| Year | Count |
|---|---|
| 1957 | 22 |
| 1958 | 42 |
| 1959 | 66 |
| 1960 | 90 |
| 1961 | 76 |
| 1963 | 70 |
| 1964 | 45 |
| 1965 | 39 |
| 1966 | 42 |
| 1967 | 62 |
| 1968 | 78 |
| 1969 | 75 |
| 1970 | 65 |
| 1971 | 53 |
| 1972 | 70 |
| 1973 | 29 |
| 1974 | 39 |
| 1975 | 29 |
| 1976 | 29 |
| 1977 | 62 |
| 1978 | 30 |
| 1979 | 40 |
| 1980 | 36 |
| 1981 | 18 |
| 1982 | 12 |
| 1983 | 8 |
| 1984 | 10 |
| 1985 | 5 |
| 1987 | 6 |
| 1989 | 5 |
| 1990 | 5 |