Year	current US$
1976	20379493533.0367
1977	19789622943.6286
1978	8207539953.56232
1979	12847081474.254
1980	5278335858.39745
1981	-1153788036.27503
1982	5910387949.80753
1983	10865851960.4179
1984	6869765460.38843
1985	2933075469.3259
1986	-9856726270.59752
1987	-1953642007.52785
1988	-10638797039.7134
1989	608385200.885315
1990	5789600960.97214
1993	10370171660.9542
1994	11823651430.5178
1995	15321812531.0356
1996	26891238171.6417
1997	21811367119.2334
1998	13884936167.688
1999	23839344446.5382
2000	24908927492.4892