| Year | Count |
|---|---|
| 1921 | 5 |
| 1925 | 5 |
| 1930 | 5 |
| 1932 | 10 |
| 1933 | 18 |
| 1934 | 8 |
| 1935 | 28 |
| 1936 | 15 |
| 1937 | 36 |
| 1938 | 37 |
| 1939 | 26 |
| 1940 | 18 |
| 1941 | 50 |
| 1942 | 107 |
| 1943 | 106 |
| 1944 | 125 |
| 1945 | 111 |
| 1946 | 157 |
| 1947 | 249 |
| 1948 | 162 |
| 1949 | 69 |
| 1950 | 94 |
| 1951 | 100 |
| 1952 | 88 |
| 1953 | 88 |
| 1954 | 182 |
| 1955 | 215 |
| 1956 | 274 |
| 1957 | 282 |
| 1958 | 443 |
| 1959 | 467 |
| 1960 | 441 |
| 1961 | 302 |
| 1962 | 317 |
| 1963 | 298 |
| 1964 | 332 |
| 1965 | 187 |
| 1966 | 127 |
| 1967 | 95 |
| 1968 | 59 |
| 1969 | 29 |
| 1970 | 53 |
| 1971 | 19 |
| 1972 | 10 |
| 1973 | 27 |
| 1974 | 15 |
| 1975 | 14 |
| 1977 | 11 |
| 1978 | 15 |
| 1981 | 8 |
| 1983 | 5 |