| Year | Count |
|---|---|
| 1949 | 5 |
| 1952 | 7 |
| 1953 | 64 |
| 1954 | 120 |
| 1955 | 124 |
| 1956 | 205 |
| 1957 | 222 |
| 1958 | 415 |
| 1959 | 584 |
| 1960 | 636 |
| 1961 | 874 |
| 1962 | 647 |
| 1963 | 650 |
| 1964 | 649 |
| 1965 | 482 |
| 1966 | 389 |
| 1967 | 298 |
| 1968 | 323 |
| 1969 | 306 |
| 1970 | 240 |
| 1971 | 233 |
| 1972 | 83 |
| 1973 | 62 |
| 1974 | 59 |
| 1975 | 25 |
| 1976 | 25 |
| 1977 | 17 |
| 1978 | 5 |
| 1979 | 12 |
| 1980 | 5 |