| Year | Count |
|---|---|
| 1958 | 5 |
| 1962 | 5 |
| 1963 | 6 |
| 1964 | 10 |
| 1965 | 10 |
| 1966 | 42 |
| 1967 | 48 |
| 1968 | 66 |
| 1969 | 111 |
| 1970 | 95 |
| 1971 | 111 |
| 1972 | 142 |
| 1973 | 119 |
| 1974 | 129 |
| 1975 | 122 |
| 1976 | 114 |
| 1977 | 117 |
| 1978 | 94 |
| 1979 | 127 |
| 1980 | 119 |
| 1981 | 123 |
| 1982 | 136 |
| 1983 | 155 |
| 1984 | 79 |
| 1985 | 110 |
| 1986 | 80 |
| 1987 | 73 |
| 1988 | 71 |
| 1989 | 44 |
| 1990 | 28 |
| 1991 | 36 |
| 1992 | 7 |
| 1993 | 7 |
| 1994 | 8 |
| 1995 | 5 |
| 1997 | 7 |
| 1998 | 6 |
| 2000 | 10 |
| 2001 | 5 |
| 2002 | 5 |