| Year | Count |
|---|---|
| 1939 | 5 |
| 1940 | 5 |
| 1941 | 7 |
| 1945 | 20 |
| 1946 | 26 |
| 1947 | 24 |
| 1948 | 53 |
| 1949 | 41 |
| 1950 | 157 |
| 1951 | 251 |
| 1952 | 290 |
| 1953 | 368 |
| 1954 | 387 |
| 1955 | 464 |
| 1956 | 421 |
| 1957 | 330 |
| 1958 | 290 |
| 1959 | 327 |
| 1960 | 319 |
| 1961 | 374 |
| 1962 | 233 |
| 1963 | 205 |
| 1964 | 191 |
| 1965 | 137 |
| 1966 | 104 |
| 1967 | 131 |
| 1968 | 126 |
| 1969 | 117 |
| 1970 | 141 |
| 1971 | 102 |
| 1972 | 57 |
| 1973 | 86 |
| 1974 | 62 |
| 1975 | 47 |
| 1976 | 55 |
| 1977 | 21 |
| 1978 | 26 |
| 1979 | 73 |
| 1980 | 62 |
| 1981 | 42 |
| 1982 | 44 |
| 1983 | 42 |
| 1984 | 46 |
| 1985 | 144 |
| 1986 | 86 |
| 1987 | 65 |
| 1988 | 21 |
| 1989 | 6 |
| 1995 | 9 |
| 2012 | 14 |