| Year | Count |
|---|---|
| 1918 | 8 |
| 1920 | 5 |
| 1925 | 10 |
| 1926 | 18 |
| 1927 | 20 |
| 1928 | 12 |
| 1929 | 14 |
| 1933 | 7 |
| 1934 | 6 |
| 1935 | 5 |
| 1936 | 6 |
| 1938 | 7 |
| 1939 | 7 |
| 1940 | 9 |
| 1941 | 7 |
| 1942 | 5 |
| 1943 | 6 |
| 1944 | 9 |
| 1945 | 7 |
| 1947 | 8 |
| 1948 | 11 |
| 1949 | 7 |
| 1950 | 10 |
| 1951 | 13 |
| 1952 | 7 |
| 1953 | 16 |
| 1954 | 9 |
| 1955 | 18 |
| 1956 | 14 |
| 1957 | 32 |
| 1958 | 30 |
| 1959 | 30 |
| 1960 | 34 |
| 1961 | 28 |
| 1962 | 12 |
| 1963 | 23 |
| 1964 | 23 |
| 1965 | 16 |
| 1966 | 12 |
| 1967 | 12 |
| 1968 | 12 |
| 1969 | 13 |
| 1970 | 5 |
| 1971 | 9 |
| 1972 | 9 |