| Year | Count |
|---|---|
| 1966 | 5 |
| 1968 | 12 |
| 1969 | 17 |
| 1970 | 20 |
| 1971 | 48 |
| 1972 | 79 |
| 1973 | 79 |
| 1974 | 61 |
| 1975 | 74 |
| 1976 | 54 |
| 1977 | 61 |
| 1978 | 38 |
| 1979 | 71 |
| 1980 | 16 |
| 1981 | 23 |
| 1982 | 35 |
| 1983 | 40 |
| 1984 | 41 |
| 1985 | 57 |
| 1986 | 24 |
| 1987 | 20 |
| 1988 | 33 |
| 1989 | 23 |
| 1990 | 6 |
| 1991 | 25 |
| 1992 | 20 |
| 1993 | 30 |
| 1995 | 25 |
| 1996 | 16 |
| 1997 | 12 |
| 2000 | 6 |
| 2006 | 6 |