| Year | Count |
|---|---|
| 1923 | 7 |
| 1924 | 6 |
| 1925 | 7 |
| 1926 | 5 |
| 1927 | 6 |
| 1928 | 5 |
| 1929 | 8 |
| 1930 | 7 |
| 1931 | 8 |
| 1939 | 7 |
| 1940 | 9 |
| 1941 | 8 |
| 1943 | 12 |
| 1945 | 7 |
| 1946 | 11 |
| 1948 | 5 |
| 1949 | 8 |
| 1956 | 22 |
| 1957 | 20 |
| 1958 | 16 |
| 1959 | 20 |
| 1962 | 12 |
| 1963 | 10 |
| 1964 | 12 |
| 1966 | 10 |
| 1967 | 26 |
| 1969 | 6 |
| 1973 | 8 |
| 1975 | 9 |
| 1980 | 10 |
| 1981 | 8 |
| 1982 | 6 |
| 1985 | 5 |
| 1986 | 6 |
| 1987 | 5 |
| 1991 | 6 |
| 1993 | 8 |
| 1994 | 7 |
| 1995 | 8 |
| 1997 | 6 |
| 1998 | 6 |
| 2005 | 7 |
| 2008 | 16 |
| 2009 | 6 |