| Year | Count |
|---|---|
| 1940 | 34 |
| 1941 | 67 |
| 1942 | 168 |
| 1943 | 209 |
| 1944 | 233 |
| 1945 | 245 |
| 1946 | 363 |
| 1947 | 497 |
| 1948 | 596 |
| 1949 | 636 |
| 1950 | 764 |
| 1951 | 1,013 |
| 1952 | 1,109 |
| 1953 | 1,124 |
| 1954 | 1,173 |
| 1955 | 965 |
| 1956 | 694 |
| 1957 | 640 |
| 1958 | 702 |
| 1959 | 573 |
| 1960 | 541 |
| 1961 | 437 |
| 1962 | 298 |
| 1963 | 231 |
| 1964 | 222 |
| 1965 | 156 |
| 1966 | 98 |
| 1967 | 148 |
| 1968 | 101 |
| 1969 | 139 |
| 1970 | 167 |
| 1971 | 155 |
| 1972 | 66 |
| 1973 | 49 |
| 1974 | 30 |
| 1975 | 37 |
| 1977 | 10 |
| 1978 | 15 |
| 1980 | 7 |
| 1981 | 6 |
| 1990 | 5 |
| 1991 | 6 |
| 1994 | 5 |
| 1997 | 11 |