| Year | Count |
|---|---|
| 1929 | 6 |
| 1937 | 6 |
| 1938 | 6 |
| 1939 | 5 |
| 1946 | 5 |
| 1950 | 5 |
| 1958 | 6 |
| 1962 | 8 |
| 1967 | 5 |
| 1968 | 5 |
| 1969 | 12 |
| 1970 | 15 |
| 1971 | 6 |
| 1972 | 5 |
| 1973 | 31 |
| 1974 | 11 |
| 1975 | 5 |
| 1976 | 10 |
| 1977 | 18 |
| 1978 | 14 |
| 1979 | 34 |
| 1980 | 36 |
| 1981 | 41 |
| 1982 | 18 |
| 1983 | 41 |
| 1984 | 19 |
| 1985 | 15 |
| 1986 | 18 |
| 1987 | 25 |
| 1989 | 5 |
| 1990 | 14 |
| 1996 | 5 |