Year	current US$
1970	1857363400
1971	2255959900
1972	2654199160.545645
1973	3258402050.6634502
1974	3719910243.902439
1975	4251739756.0975614
1976	4499232764.920829
1977	4635330843.373494
1978	5819724675.324676
1979	6377068904.10959
1980	6521956666.666667
1981	6565420000
1982	6838236470.588236
1983	7224138183.934808
1984	7766066363.118953
1985	7725366415.547548
1986	7687511279.0976715
1987	8295404425.791682
1988	8794332849.604221
1989	8421585287.709855
1990	8662106515.957447
1991	5332907602.019926
1992	3736544459.4594593
1993	2951182567.567568
1994	3766477027.027027
1995	4078053746.967956
1996	3831000000
1997	3785600000
1998	3668100000
1999	4123500000
2000	4318900000
2001	4193000000
2002	3872000000
2003	4649900000
2004	6120800000
2005	8962900000
2006	9138888888.888887
2007	11035092592.592592
2008	11580000000
2009	10036111111.11111
2010	13443518518.518518
2011	17319000000
2012	18659000000
2013	18593000000
2014	17812000000
2015	14941000000
2016	13690000000
2017	14093000000
2018	14530000000
2019	12632000000
2020	8769000000