| Year | Count |
|---|---|
| 1948 | 6 |
| 1950 | 10 |
| 1951 | 22 |
| 1952 | 58 |
| 1953 | 81 |
| 1954 | 210 |
| 1955 | 246 |
| 1956 | 477 |
| 1957 | 474 |
| 1958 | 661 |
| 1959 | 606 |
| 1960 | 564 |
| 1961 | 485 |
| 1962 | 607 |
| 1963 | 551 |
| 1964 | 635 |
| 1965 | 554 |
| 1966 | 578 |
| 1967 | 508 |
| 1968 | 619 |
| 1969 | 663 |
| 1970 | 726 |
| 1971 | 658 |
| 1972 | 444 |
| 1973 | 329 |
| 1974 | 279 |
| 1975 | 293 |
| 1976 | 239 |
| 1977 | 148 |
| 1978 | 134 |
| 1979 | 146 |
| 1980 | 79 |
| 1981 | 102 |
| 1982 | 100 |
| 1983 | 52 |
| 1984 | 74 |
| 1985 | 74 |
| 1986 | 59 |
| 1987 | 61 |
| 1988 | 45 |
| 1989 | 53 |
| 1990 | 17 |
| 1991 | 24 |
| 1992 | 24 |
| 1993 | 15 |
| 1994 | 5 |
| 1996 | 15 |
| 1997 | 17 |
| 1999 | 5 |