| Year | Count |
|---|---|
| 1954 | 7 |
| 1956 | 5 |
| 1957 | 10 |
| 1958 | 10 |
| 1959 | 10 |
| 1961 | 5 |
| 1962 | 14 |
| 1963 | 26 |
| 1964 | 36 |
| 1965 | 11 |
| 1966 | 14 |
| 1967 | 13 |
| 1968 | 28 |
| 1969 | 74 |
| 1970 | 106 |
| 1971 | 178 |
| 1972 | 143 |
| 1973 | 128 |
| 1974 | 222 |
| 1975 | 192 |
| 1976 | 181 |
| 1977 | 160 |
| 1978 | 172 |
| 1979 | 331 |
| 1980 | 200 |
| 1981 | 107 |
| 1982 | 134 |
| 1983 | 88 |
| 1984 | 26 |
| 1985 | 77 |
| 1986 | 85 |
| 1987 | 59 |
| 1988 | 15 |
| 1989 | 10 |
| 1991 | 6 |