1964     409.4         76              282.9
1965     463.1         82              335.6
1966     359.1         80              381.3
1967     317.3         76              404.7
1968     373.5         69              382.3
1969     523.7         72              411.0
1970     548.1         73              400.0
1971     728.2         82              472.9
1972     501.7         75              447.5
1973     486.1         65              426.2
1974     578.6         71              485.5
1975     542.6         78              536.9
1976     561.2         81              575.9
1977     447.1         80              532.7
1978     820.0         80              574.3
1979     777.9         77              533.9