Year	current US$
1977	-41212983.9623131
1978	-51167566.2298201
1979	-52806461.0915576
1980	-113319962.663918
1981	-33377644.1719192
1982	-85746185.9370752
1983	-35662847.7488983
1984	-29800483.1219931
1985	7567947.4117443
1986	-26974683.6249857
1987	-45869597.6358479
1988	-12408137.0095892
1989	15199729.6076284
1990	1974365.24038142
1991	-18739783.938196
1992	-18336735.73091
1993	16371054.0342222
1994	51721155.5215523