| Year | Count |
|---|---|
| 1966 | 11 |
| 1967 | 9 |
| 1968 | 160 |
| 1969 | 275 |
| 1970 | 292 |
| 1971 | 241 |
| 1972 | 210 |
| 1973 | 151 |
| 1974 | 97 |
| 1975 | 110 |
| 1976 | 211 |
| 1977 | 174 |
| 1978 | 153 |
| 1978 | 5 |
| 1979 | 143 |
| 1980 | 152 |
| 1981 | 68 |
| 1982 | 100 |
| 1983 | 60 |
| 1984 | 56 |
| 1985 | 99 |
| 1986 | 27 |
| 1987 | 53 |
| 1988 | 7 |
| 1989 | 26 |
| 1990 | 27 |
| 1991 | 11 |
| 1992 | 58 |
| 1993 | 54 |
| 1994 | 46 |
| 1995 | 14 |
| 1996 | 24 |
| 1997 | 17 |
| 1999 | 5 |