| Year | Count |
|---|---|
| 1957 | 165 |
| 1958 | 395 |
| 1959 | 587 |
| 1960 | 622 |
| 1961 | 702 |
| 1962 | 758 |
| 1963 | 741 |
| 1964 | 731 |
| 1965 | 675 |
| 1966 | 550 |
| 1967 | 677 |
| 1968 | 1,041 |
| 1969 | 968 |
| 1970 | 1,014 |
| 1971 | 918 |
| 1972 | 807 |
| 1973 | 654 |
| 1974 | 491 |
| 1975 | 387 |
| 1976 | 340 |
| 1977 | 264 |
| 1978 | 191 |
| 1979 | 190 |
| 1980 | 205 |
| 1981 | 117 |
| 1982 | 107 |
| 1983 | 68 |
| 1984 | 71 |
| 1985 | 46 |
| 1986 | 35 |
| 1987 | 51 |
| 1988 | 22 |
| 1992 | 5 |
| 1994 | 15 |