Year	current US$
1960	16939983.144006744
1961	18003977.118409153
1962	19109972.196011122
1963	20285973.965610415
1964	21517968.992812403
1965	24513990.194403924
1966	25871989.65120414
1967	27285989.085604366
1968	32045987.181605127
1969	34400000
1970	36214427.428571425
1971	40218373.47749713
1972	47191131.96396913
1973	60845339.48897556
1974	75440826.05242255
1975	71231613.66163622
1976	75981415.09134233
1977	41449419.13043478
1978	71408702.76243094
1979	76377818.37270342
1980	35787498.69705709
1981	56436271.40139505
1982	54492988.42561796
1983	61735888.79584659
1984	32128184.573351208
1985	41131621.18780096
1986	55559842.58044602
1987	44217482.72754581
1988	39205646.783454634
1989	48754296.28241175
1990	37941635.96069766