| Year | Count |
|---|---|
| 1955 | 10 |
| 1959 | 29 |
| 1960 | 60 |
| 1961 | 47 |
| 1962 | 47 |
| 1963 | 70 |
| 1964 | 90 |
| 1965 | 127 |
| 1966 | 85 |
| 1967 | 97 |
| 1968 | 118 |
| 1969 | 30 |
| 1970 | 109 |
| 1971 | 57 |
| 1972 | 41 |
| 1973 | 40 |
| 1974 | 27 |
| 1975 | 15 |
| 1976 | 10 |
| 1977 | 22 |
| 1978 | 21 |
| 1979 | 19 |
| 1980 | 18 |
| 1982 | 17 |
| 1983 | 8 |
| 1984 | 10 |
| 1985 | 20 |
| 1986 | 28 |
| 1987 | 31 |
| 1988 | 121 |
| 1989 | 63 |
| 1990 | 64 |
| 1991 | 27 |
| 1992 | 17 |
| 1994 | 5 |
| 1996 | 5 |