Year	constant 2015 US$
1970	13329.051773890023
1971	13626.048184463334
1972	14221.426802736756
1973	14883.631978902029
1974	14409.718747444698
1975	14324.257043245729
1976	14871.853792114607
1977	15243.81425473167
1978	15843.992730400736
1979	15947.86371961736
1980	15674.347327683188
1981	15821.985148470272
1982	15902.58044652244
1983	16218.08839525729
1984	16946.435458704385
1985	17481.27513817617
1986	18141.89048777429
1987	18690.742325272495
1988	19587.599991394294
1989	20052.34302850232
1990	20430.45300380906
1991	20550.54990410983
1992	20834.76708898465
1993	20785.571913721906
1994	21369.596862357546
1995	21890.676896072586
1996	22522.027406270518
1997	23255.493414776338
1998	23938.72301406414
1999	24621.12497678334
2000	25436.83714078369
2001	25746.280381539193
2002	25979.947251923004
2003	26361.356966211195
2004	27183.620288346276
2005	27755.047165160107
2006	28538.836545075985
2007	28924.274229066803
2008	28215.652753621576
2009	27137.883374602556
2010	28099.577006565218
2011	28494.603199163
2012	28887.13152714694
2013	29134.245598596037
2014	29698.040781494903
2015	30325.09831018893
2016	30633.580742778457
2017	31327.61910470752
2018	31849.83615531849
2019	32236.64279279069
2020	30557.401589184818
2021	32000.177401635312