Year	current US$
1970	15733456.3665714
1971	16038029.64
1972	17893638.1394626
1973	17935714.4232857
1974	22322994.9817142
1975	26493453.4474285
1976	34071713.0485714
1977	37745998.4802857
1978	40904700.4575
1979	41699052.7973685
1980	55659221.0185263
1981	79446154.0145
1982	80705129.0636955
1983	82144268.3533334
1984	154975647.288207
1985	135810879.942558
1986	160752721.88247
1987	176199951.490267
1988	83768933.2845405
1989	24827049.3407296
1990	35422649.904929
1991	41553416.8875012
1992	53193400
1993	51512421.1428848
1994	47444279.1666666
1995	56549281.0756973
1996	59760778.5417901
1997	150581265.413368
1998	145873632.54595
1999	140865292.599969
2000	135836141.359217
2001	127809235.472222
2002	113413874.196491
2003	127593931.662472
2004	152414335.166351
2005	182054388.925081
2006	208219092.987761
2007	246468435.99751
2008	301309976.50205
2009	311487794.352863
2010	349091979.495608
2011	389729921.281824
2012	414764501.161523
2013	428399979.694857
2014	468733896.917818
2015	502975939.229842
2016	518727267.258308
2017	536042565.673576
2018	507294629.308598
2019	497339653.692294
2020	482191574.516408
2021	537687205.774644