| Year | Count |
|---|---|
| 1938 | 5 |
| 1939 | 29 |
| 1940 | 6 |
| 1942 | 24 |
| 1943 | 33 |
| 1944 | 48 |
| 1945 | 55 |
| 1946 | 64 |
| 1947 | 128 |
| 1948 | 109 |
| 1949 | 92 |
| 1950 | 120 |
| 1951 | 165 |
| 1952 | 210 |
| 1953 | 193 |
| 1954 | 149 |
| 1955 | 134 |
| 1956 | 178 |
| 1957 | 125 |
| 1958 | 119 |
| 1959 | 105 |
| 1960 | 125 |
| 1961 | 143 |
| 1962 | 68 |
| 1963 | 62 |
| 1964 | 70 |
| 1965 | 86 |
| 1966 | 96 |
| 1967 | 90 |
| 1968 | 54 |
| 1969 | 55 |
| 1970 | 58 |
| 1971 | 23 |
| 1972 | 22 |
| 1973 | 8 |
| 1974 | 10 |
| 1975 | 7 |
| 1979 | 5 |
| 1980 | 16 |
| 1983 | 5 |
| 1987 | 14 |
| 1989 | 5 |
| 1992 | 5 |
| 1993 | 10 |
| 1995 | 5 |
| 1996 | 8 |
| 1997 | 7 |
| 1998 | 27 |
| 1999 | 5 |
| 2000 | 10 |
| 2001 | 6 |
| 2004 | 12 |
| 2007 | 16 |
| 2010 | 5 |