1930 286 2323 8.7 4.2 1935 263 2067 20.1 9.5 1940 348 2630 14.6 9.2 1945 564 4032 1 9 4.4 1950 534 3517 5.3 8.2 1955 655 3962 4.4 8.2 1960 737 4078 5.5 10.3 1965 926 4765 4.5 11.2 1970 1075 5248 4.9 14.8