| Year | Count |
|---|---|
| 1958 | 5 |
| 1961 | 7 |
| 1962 | 51 |
| 1964 | 28 |
| 1965 | 92 |
| 1966 | 94 |
| 1967 | 63 |
| 1968 | 64 |
| 1969 | 59 |
| 1970 | 70 |
| 1971 | 78 |
| 1972 | 68 |
| 1973 | 48 |
| 1974 | 57 |
| 1975 | 29 |
| 1976 | 85 |
| 1977 | 185 |
| 1978 | 133 |
| 1979 | 155 |
| 1980 | 122 |
| 1981 | 95 |
| 1982 | 73 |
| 1983 | 114 |
| 1984 | 55 |
| 1985 | 72 |
| 1986 | 90 |
| 1987 | 91 |
| 1988 | 59 |
| 1989 | 34 |
| 1990 | 5 |
| 1991 | 17 |
| 1992 | 10 |
| 1993 | 20 |
| 1994 | 10 |
| 1995 | 6 |