| Year | Count |
|---|---|
| 1915 | 5 |
| 1916 | 6 |
| 1917 | 5 |
| 1919 | 10 |
| 1921 | 5 |
| 1924 | 5 |
| 1925 | 9 |
| 1926 | 16 |
| 1927 | 16 |
| 1928 | 20 |
| 1929 | 24 |
| 1930 | 24 |
| 1931 | 8 |
| 1932 | 25 |
| 1933 | 11 |
| 1934 | 24 |
| 1935 | 31 |
| 1936 | 42 |
| 1937 | 7 |
| 1938 | 8 |
| 1939 | 9 |
| 1940 | 31 |
| 1941 | 28 |
| 1942 | 29 |
| 1943 | 10 |
| 1944 | 27 |
| 1945 | 49 |
| 1946 | 25 |
| 1947 | 24 |
| 1948 | 36 |
| 1949 | 50 |
| 1950 | 22 |
| 1951 | 67 |
| 1952 | 33 |
| 1953 | 26 |
| 1954 | 57 |
| 1955 | 57 |
| 1956 | 60 |
| 1957 | 39 |
| 1958 | 50 |
| 1959 | 69 |
| 1960 | 56 |
| 1961 | 32 |
| 1962 | 43 |
| 1963 | 32 |
| 1964 | 35 |
| 1965 | 19 |
| 1966 | 35 |
| 1967 | 7 |
| 1968 | 5 |
| 1969 | 7 |