| Year | Count |
|---|---|
| 1946 | 31 |
| 1947 | 23 |
| 1948 | 25 |
| 1949 | 36 |
| 1950 | 11 |
| 1951 | 64 |
| 1952 | 56 |
| 1953 | 67 |
| 1954 | 73 |
| 1955 | 228 |
| 1956 | 381 |
| 1957 | 293 |
| 1958 | 313 |
| 1959 | 279 |
| 1960 | 231 |
| 1961 | 166 |
| 1962 | 248 |
| 1963 | 211 |
| 1964 | 185 |
| 1965 | 188 |
| 1966 | 120 |
| 1967 | 83 |
| 1968 | 101 |
| 1969 | 66 |
| 1970 | 47 |
| 1971 | 74 |
| 1972 | 57 |
| 1973 | 48 |
| 1974 | 84 |
| 1975 | 6 |
| 1976 | 5 |
| 1977 | 5 |
| 1978 | 5 |
| 1980 | 22 |
| 1981 | 72 |
| 1982 | 40 |
| 1983 | 17 |
| 1984 | 22 |
| 1985 | 92 |
| 1989 | 5 |
| 1990 | 5 |
| 1991 | 7 |