| Year | Count |
|---|---|
| 1954 | 6 |
| 1955 | 19 |
| 1956 | 24 |
| 1957 | 10 |
| 1958 | 79 |
| 1959 | 77 |
| 1960 | 163 |
| 1961 | 191 |
| 1962 | 260 |
| 1963 | 343 |
| 1964 | 370 |
| 1965 | 287 |
| 1966 | 339 |
| 1967 | 363 |
| 1968 | 417 |
| 1969 | 380 |
| 1970 | 315 |
| 1971 | 428 |
| 1972 | 331 |
| 1973 | 201 |
| 1974 | 188 |
| 1975 | 134 |
| 1976 | 59 |
| 1977 | 126 |
| 1978 | 93 |
| 1979 | 57 |
| 1980 | 74 |
| 1981 | 27 |
| 1982 | 53 |
| 1983 | 61 |
| 1984 | 18 |
| 1985 | 53 |
| 1987 | 16 |
| 1988 | 7 |
| 1991 | 10 |