1? _ 3000 1934 to 1940 3000 _ 5500 1940 to 1945 5500 _ 8000 1945 to 1950 8000 _ 12000 1950 to 1955 12000 _ 16000 1955 to 1960 16000 _ 19000 1960 to 1965 19000 _ 22000 1965 to 1970 22000 _ 24000 1970 to 1975 24000 _ 26000 1975 to 1980 26000 _ >27000 1980 to 1982