| Year | Count |
|---|---|
| 1915 | 7 |
| 1916 | 12 |
| 1918 | 5 |
| 1920 | 9 |
| 1921 | 9 |
| 1922 | 24 |
| 1923 | 26 |
| 1924 | 28 |
| 1925 | 32 |
| 1926 | 34 |
| 1927 | 32 |
| 1928 | 52 |
| 1929 | 44 |
| 1930 | 50 |
| 1931 | 16 |
| 1932 | 21 |
| 1933 | 17 |
| 1934 | 18 |
| 1935 | 24 |
| 1936 | 18 |
| 1937 | 20 |
| 1938 | 22 |
| 1939 | 21 |
| 1940 | 26 |
| 1941 | 22 |
| 1942 | 23 |
| 1943 | 18 |
| 1944 | 20 |
| 1945 | 22 |
| 1946 | 18 |
| 1947 | 27 |
| 1948 | 18 |
| 1949 | 29 |
| 1950 | 17 |
| 1951 | 16 |
| 1952 | 22 |
| 1953 | 19 |
| 1954 | 19 |
| 1955 | 15 |
| 1956 | 17 |
| 1957 | 34 |
| 1958 | 58 |
| 1959 | 62 |
| 1960 | 36 |
| 1961 | 48 |
| 1963 | 7 |
| 1964 | 13 |
| 1965 | 8 |
| 1966 | 8 |
| 1967 | 5 |
| 1968 | 6 |