| Year | Count |
|---|---|
| 1949 | 9 |
| 1950 | 11 |
| 1951 | 15 |
| 1952 | 11 |
| 1953 | 38 |
| 1954 | 75 |
| 1955 | 170 |
| 1956 | 229 |
| 1957 | 244 |
| 1958 | 345 |
| 1959 | 371 |
| 1960 | 384 |
| 1961 | 319 |
| 1962 | 242 |
| 1963 | 267 |
| 1964 | 214 |
| 1965 | 197 |
| 1966 | 233 |
| 1967 | 225 |
| 1968 | 258 |
| 1969 | 246 |
| 1970 | 241 |
| 1971 | 164 |
| 1972 | 186 |
| 1973 | 171 |
| 1974 | 180 |
| 1975 | 108 |
| 1976 | 68 |
| 1977 | 95 |
| 1978 | 64 |
| 1979 | 106 |
| 1980 | 134 |
| 1981 | 128 |
| 1982 | 120 |
| 1983 | 95 |
| 1984 | 94 |
| 1985 | 144 |
| 1986 | 101 |
| 1987 | 108 |
| 1988 | 74 |
| 1989 | 49 |
| 1990 | 69 |
| 1991 | 81 |
| 1992 | 17 |
| 1993 | 5 |
| 1994 | 16 |
| 2000 | 10 |