| Year | Count |
|---|---|
| 1959 | 14 |
| 1960 | 43 |
| 1961 | 44 |
| 1962 | 68 |
| 1963 | 34 |
| 1964 | 54 |
| 1965 | 29 |
| 1966 | 11 |
| 1967 | 48 |
| 1968 | 71 |
| 1969 | 103 |
| 1970 | 85 |
| 1971 | 146 |
| 1972 | 92 |
| 1973 | 120 |
| 1974 | 143 |
| 1975 | 147 |
| 1976 | 126 |
| 1977 | 110 |
| 1978 | 39 |
| 1979 | 50 |
| 1980 | 21 |
| 1981 | 26 |
| 1982 | 30 |
| 1983 | 25 |
| 1984 | 18 |
| 1985 | 9 |
| 1986 | 12 |
| 1987 | 31 |
| 1988 | 10 |
| 1989 | 15 |
| 1997 | 5 |