| Year | Count |
|---|---|
| 1921 | 5 |
| 1922 | 8 |
| 1923 | 8 |
| 1924 | 7 |
| 1925 | 5 |
| 1926 | 6 |
| 1927 | 6 |
| 1928 | 6 |
| 1929 | 8 |
| 1930 | 9 |
| 1939 | 5 |
| 1940 | 12 |
| 1941 | 8 |
| 1942 | 6 |
| 1943 | 5 |
| 1944 | 7 |
| 1945 | 5 |
| 1946 | 14 |
| 1947 | 24 |
| 1948 | 5 |
| 1949 | 10 |
| 1955 | 33 |
| 1956 | 12 |
| 1957 | 14 |
| 1958 | 16 |
| 1960 | 14 |
| 1963 | 12 |
| 1964 | 12 |
| 1965 | 12 |
| 1966 | 10 |
| 1969 | 5 |
| 1970 | 6 |
| 1971 | 8 |
| 1973 | 8 |
| 1974 | 5 |
| 1975 | 8 |
| 1978 | 9 |
| 1980 | 6 |
| 1984 | 7 |
| 1987 | 5 |
| 1988 | 8 |
| 1989 | 6 |
| 1991 | 6 |
| 1992 | 7 |
| 1995 | 8 |
| 1996 | 5 |
| 1997 | 10 |
| 1999 | 7 |
| 2000 | 5 |
| 2001 | 18 |
| 2006 | 9 |
| 2010 | 6 |
| 2011 | 12 |
| 2012 | 10 |