| Year | Count |
|---|---|
| 1969 | 10 |
| 1971 | 7 |
| 1972 | 39 |
| 1973 | 7 |
| 1974 | 6 |
| 1975 | 10 |
| 1976 | 5 |
| 1977 | 24 |
| 1978 | 25 |
| 1979 | 54 |
| 1980 | 64 |
| 1981 | 29 |
| 1982 | 68 |
| 1983 | 71 |
| 1984 | 37 |
| 1985 | 52 |
| 1986 | 88 |
| 1987 | 80 |
| 1988 | 118 |
| 1989 | 106 |
| 1990 | 96 |
| 1991 | 148 |
| 1992 | 66 |
| 1993 | 70 |
| 1994 | 40 |
| 1995 | 18 |
| 1996 | 25 |
| 1997 | 5 |
| 1998 | 5 |
| 2000 | 15 |
| 2001 | 5 |
| 2002 | 5 |