Year	current US$
1970	2515236800
1971	3055095900
1972	3594369359.9160547
1973	4412339083.232811
1974	5038233170.731708
1975	5756838292.682927
1976	6093814738.124239
1977	6276949156.626506
1978	7878465454.545454
1979	8645207123.287672
1980	8817697500
1981	8905963975.903614
1982	9251183529.411764
1983	9765161117.57858
1984	10603443141.71884
1985	10307791680.314444
1986	10606362970.962322
1987	11073229683.326975
1988	11837456728.23219
1989	12096964757.144688
1990	11708950531.914894
1991	7067591647.331786
1992	4025942837.8378377
1993	3516494864.864865
1994	4135300810.810811
1995	4840440188.94421
1996	4331000000
1997	4522800000
1998	4697400000
1999	4916000000
2000	5179600000
2001	5109300000
2002	4434700000
2003	4895200000
2004	5841100000
2005	7822300000
2006	9022222222.222221
2007	9567222222.222221
2008	13709351851.85185
2009	8883333333.333332
2010	10555555555.555555
2011	15079000000
2012	14888000000
2013	15602000000
2014	13865000000
2015	12605000000
2016	11226000000
2017	11304000000
2018	12567000000
2019	10971000000
2020	8067000000