| Year | Count |
|---|---|
| 1965 | 5 |
| 1966 | 6 |
| 1968 | 14 |
| 1969 | 22 |
| 1970 | 95 |
| 1971 | 105 |
| 1972 | 137 |
| 1973 | 129 |
| 1974 | 185 |
| 1975 | 153 |
| 1976 | 172 |
| 1977 | 366 |
| 1978 | 458 |
| 1979 | 377 |
| 1980 | 340 |
| 1981 | 313 |
| 1982 | 213 |
| 1983 | 179 |
| 1984 | 227 |
| 1985 | 311 |
| 1986 | 239 |
| 1987 | 226 |
| 1988 | 165 |
| 1989 | 168 |
| 1990 | 141 |
| 1991 | 55 |
| 1992 | 45 |
| 1993 | 59 |
| 1994 | 34 |
| 1995 | 24 |
| 2000 | 12 |