Year	constant 2015 US$
1970	22009.419771289966
1971	22313.052158452454
1972	23291.8400420797
1973	24357.422116764526
1974	23221.00854844901
1975	22955.657230156932
1976	23884.14868257991
1977	24555.854132658773
1978	25498.46834226593
1979	25094.82810938419
1980	24365.397972104907
1981	25133.952178230928
1982	25098.073545456133
1983	25667.423639822864
1984	27451.672023262083
1985	28356.093581815603
1986	29045.21629643228
1987	29852.430821040616
1988	31254.926586234953
1989	31655.959715279714
1990	31648.639222321468
1991	31282.871174804324
1992	31841.052248623084
1993	32152.014538230447
1994	33180.17250017179
1995	33907.98016030259
1996	34904.43204382346
1997	36333.90884967269
1998	37948.70423721917
1999	39139.03922317336
2000	40273.90138409465
2001	40468.20503903186
2002	40722.658008837505
2003	41185.37045030083
2004	42427.71945602346
2005	43227.19395060952
2006	44454.79285954487
2007	44264.11812810715
2008	42802.21479463068
2009	41786.22330104196
2010	43256.28263230128
2011	43896.00778771141
2012	45152.24642137758
2013	45501.379867553835
2014	46627.92691128064
2015	47711.34897867334
2016	47833.797236793
2017	48876.25804795338
2018	49966.86472644713
2019	50798.83867797619
2020	48427.779426358255
2021	50985.28761190966