- 1937 to 1939 2
- 1940 to 1944 2
- 1945 to 1949 3
- 1950 to 1954 2
- 1955 to 1959 3
- 1960 to 1964 4
- 1965 to 1969 933
- 1970 to 1974 997
- 1975 to 1979 1,116
- 1980 to 1984 1,414
- 1985 to 1989 2,445
- 1990 to 1994 2,758
- 1995 to 1999 1,660
- 2000 to 2004 1,124
- 2005 to 2009 991