| Year | Count |
|---|---|
| 1948 | 15 |
| 1951 | 5 |
| 1952 | 24 |
| 1953 | 79 |
| 1954 | 77 |
| 1955 | 151 |
| 1956 | 184 |
| 1957 | 350 |
| 1958 | 408 |
| 1959 | 412 |
| 1960 | 479 |
| 1961 | 467 |
| 1962 | 440 |
| 1963 | 469 |
| 1964 | 416 |
| 1965 | 459 |
| 1966 | 515 |
| 1967 | 473 |
| 1968 | 352 |
| 1969 | 407 |
| 1970 | 430 |
| 1971 | 368 |
| 1972 | 259 |
| 1973 | 237 |
| 1974 | 164 |
| 1975 | 213 |
| 1976 | 158 |
| 1977 | 173 |
| 1978 | 141 |
| 1979 | 83 |
| 1980 | 12 |
| 1981 | 31 |
| 1982 | 35 |
| 1983 | 14 |
| 1984 | 12 |
| 1985 | 18 |
| 1986 | 23 |
| 1987 | 19 |
| 1988 | 12 |
| 1989 | 5 |
| 1990 | 6 |