| Year | Count |
|---|---|
| 1948 | 6 |
| 1949 | 5 |
| 1950 | 26 |
| 1951 | 31 |
| 1952 | 48 |
| 1953 | 82 |
| 1954 | 162 |
| 1955 | 183 |
| 1956 | 190 |
| 1957 | 237 |
| 1958 | 247 |
| 1959 | 240 |
| 1960 | 328 |
| 1961 | 311 |
| 1962 | 309 |
| 1963 | 262 |
| 1964 | 266 |
| 1965 | 269 |
| 1966 | 199 |
| 1967 | 251 |
| 1968 | 211 |
| 1969 | 167 |
| 1970 | 195 |
| 1971 | 135 |
| 1972 | 117 |
| 1973 | 68 |
| 1974 | 55 |
| 1975 | 55 |
| 1976 | 30 |
| 1977 | 5 |
| 1978 | 10 |
| 1979 | 25 |
| 1980 | 5 |
| 1981 | 16 |
| 1982 | 5 |
| 1983 | 11 |
| 1985 | 24 |
| 1986 | 12 |
| 1987 | 10 |
| 1988 | 5 |
| 1991 | 6 |
| 1993 | 5 |
| 1996 | 10 |