Year	current US$
1971	2017311021.3502595
1972	2327418570.734079
1973	3077779323.7790456
1974	3582460011.03144
1975	2991868082.2227244
1976	3353468433.359314
1977	3850103683.2230673
1978	4668687290.9699
1979	5157768205.950115
1980	5777842115.421733
1981	6357505619.848472
1982	6433357611.070648
1983	6292060988.433228
1984	5579695115.627916
1985	5707928388.746803
1986	6553654414.871145
1987	7829155060.352832
1988	8466988727.858294
1989	8178374859.442505
1990	8093587521.663778
1991	7636169255.007878
1992	7460655040.408337
1993	8390575742.492119
1994	10208193418.401613
1995	11313761955.36663
1996	11685167198.55696
1997	10784214839.563765
1998	8875203958.103058
1999	9141107478.333073
2000	8158784525.534625
2001	8183073832.245102
2002	10361772388.97925
2003	12988884817.393429
2004	15124705882.352942
2005	16663380975.850174
2006	14845989235.458141
2007	16910413757.624752
2008	16523511632.810852
2009	13071397338.996815
2010	15888789824.96401
2011	18419025893.957035
2012	18691813592.679863
2013	19540629968.859337
2014	22287420844.509644
2015	20089611046.21768
2016	19060580219.627224
2017	21058565093.04933
2018	21072357306.363964
2019	20592604792.88479
2020	19978491950.69404
2021	22348988541.51931