| Year | Count |
|---|---|
| 1921 | 8 |
| 1922 | 8 |
| 1924 | 20 |
| 1925 | 23 |
| 1926 | 27 |
| 1927 | 40 |
| 1928 | 39 |
| 1929 | 40 |
| 1930 | 44 |
| 1931 | 83 |
| 1932 | 67 |
| 1933 | 67 |
| 1934 | 103 |
| 1935 | 163 |
| 1936 | 181 |
| 1937 | 180 |
| 1938 | 230 |
| 1939 | 195 |
| 1940 | 207 |
| 1941 | 245 |
| 1942 | 342 |
| 1943 | 521 |
| 1944 | 362 |
| 1945 | 333 |
| 1946 | 587 |
| 1947 | 719 |
| 1948 | 640 |
| 1949 | 658 |
| 1950 | 873 |
| 1951 | 1,538 |
| 1952 | 1,934 |
| 1953 | 2,654 |
| 1954 | 2,634 |
| 1955 | 2,689 |
| 1956 | 3,039 |
| 1957 | 3,355 |
| 1958 | 3,871 |
| 1959 | 3,467 |
| 1960 | 3,154 |
| 1961 | 2,653 |
| 1962 | 2,627 |
| 1963 | 1,957 |
| 1964 | 1,940 |
| 1965 | 1,548 |
| 1966 | 1,176 |
| 1967 | 1,031 |
| 1968 | 816 |
| 1969 | 654 |
| 1970 | 610 |
| 1971 | 485 |
| 1972 | 321 |
| 1973 | 232 |
| 1974 | 208 |
| 1975 | 119 |
| 1976 | 82 |
| 1977 | 62 |
| 1978 | 28 |
| 1979 | 43 |
| 1980 | 19 |
| 1981 | 12 |
| 1982 | 24 |
| 1983 | 27 |
| 1984 | 27 |