| Year | Count |
|---|---|
| 1952 | 5 |
| 1954 | 15 |
| 1955 | 5 |
| 1957 | 12 |
| 1958 | 15 |
| 1959 | 18 |
| 1960 | 29 |
| 1961 | 12 |
| 1962 | 21 |
| 1963 | 31 |
| 1964 | 26 |
| 1965 | 16 |
| 1966 | 21 |
| 1967 | 17 |
| 1968 | 12 |
| 1969 | 32 |
| 1970 | 100 |
| 1971 | 121 |
| 1972 | 82 |
| 1973 | 133 |
| 1974 | 104 |
| 1975 | 116 |
| 1976 | 107 |
| 1977 | 131 |
| 1978 | 165 |
| 1979 | 51 |
| 1980 | 46 |
| 1981 | 15 |
| 1982 | 17 |
| 1983 | 19 |
| 1984 | 18 |
| 1985 | 10 |
| 1986 | 8 |
| 1988 | 10 |
| 1989 | 5 |
| 2001 | 5 |
| 2005 | 12 |
| 2006 | 10 |