Year	current US$
1970	1476022100
1971	1793453100
1972	2109814480.587618
1973	2588439083.232811
1974	2953231463.414634
1975	3381257195.1219516
1976	3583516565.164434
1977	3682578554.2168674
1978	4608346753.246753
1979	5047075342.465754
1980	5231029722.222222
1981	5268913975.903615
1982	5363843764.705882
1983	5625916414.43539
1984	6130377233.921457
1985	6592667103.395567
1986	6187691984.641229
1987	5761906142.693628
1988	6596762269.129288
1989	7114390234.525183
1990	7104782180.851064
1991	3403219325.7813563
1992	1445510405.4054055
1993	1430247702.7027028
1994	1491298513.5135136
1995	2134430103.4086556
1996	3977000000
1997	3793200000
1998	3398000000
1999	3363200000
2000	3821700000
2001	3632300000
2002	3089100000
2003	3052900000
2004	3362100000
2005	4594700000
2006	5727777777.777778
2007	5526111111.111111
2008	8357870370.37037
2009	6287037037.037037
2010	6000000000
2011	5844000000
2012	6272000000
2013	7247000000
2014	6139000000
2015	8181000000
2016	8735000000
2017	9974000000
2018	12040000000
2019	11889000000
2020	10601000000