| Year | Count |
|---|---|
| 1946 | 15 |
| 1947 | 24 |
| 1948 | 10 |
| 1949 | 31 |
| 1950 | 114 |
| 1951 | 254 |
| 1952 | 366 |
| 1953 | 381 |
| 1954 | 496 |
| 1955 | 402 |
| 1956 | 422 |
| 1957 | 489 |
| 1958 | 435 |
| 1959 | 428 |
| 1960 | 372 |
| 1961 | 306 |
| 1962 | 273 |
| 1963 | 269 |
| 1964 | 301 |
| 1965 | 184 |
| 1966 | 225 |
| 1967 | 280 |
| 1968 | 237 |
| 1969 | 263 |
| 1970 | 191 |
| 1971 | 179 |
| 1972 | 164 |
| 1973 | 157 |
| 1974 | 110 |
| 1975 | 54 |
| 1976 | 42 |
| 1977 | 99 |
| 1978 | 64 |
| 1979 | 16 |
| 1980 | 23 |
| 1981 | 22 |
| 1982 | 15 |
| 1983 | 35 |
| 1984 | 19 |
| 1985 | 33 |
| 1986 | 25 |
| 1987 | 40 |
| 1991 | 6 |
| 1996 | 9 |
| 1998 | 30 |
| 2006 | 6 |
| 2010 | 5 |