Year	current US$
1970	392.5258978671696
1971	447.41733918942566
1972	520.7526661674726
1973	682.4441208073379
1974	880.8935936845738
1975	997.0664122414415
1976	1200.0902861991603
1977	1344.0068204419829
1978	1484.2845289306808
1979	1621.2764953502215
1980	1623.607140798738
1981	1762.827599624289
1982	1820.2477331527766
1983	1259.1817190127424
1984	1272.6558566060598
1985	1105.8341362793217
1986	1356.4478138315496
1987	1454.9638753780193
1988	1599.4592698728247
1989	2150.3906823979078
1990	2137.153859131042
1991	1868.3604553602897
1992	1760.4969321281437
1993	1941.8513646493684
1994	2710.7749328591485
1995	4065.6350695205897
1996	4474.081868474057
1997	4508.4428864197325
1998	4264.07553939894
1999	2837.4693247258383
2000	3049.840015708788
2001	2553.03127528659
2002	2280.035938791091
2003	2467.2496637831036
2004	2943.664134712028
2005	3854.8432824993797
2006	4774.95962537831
2007	5996.46902170707
2008	7084.238256223078
2009	6849.15578857777
2010	8758.135584954507
2011	10109.91803187968
2012	9206.275017920672
2013	9304.493237585064
2014	9089.283144215426
2015	6552.617212535389
2016	6449.635997244662
2017	7502.893701804984
2018	6849.38818650754
2019	6679.167884003777
2020	5253.753204467887
2021	5647.133914713087