Year	current US$
1971	175.5797885295447
1972	191.3593836866945
1973	238.58130195487357
1974	290.48049330442734
1975	312.09355962249094
1976	327.01288409020697
1977	335.8537711872873
1978	369.23885988135515
1979	403.0622547598852
1980	526.2227421071116
1981	813.2089162890234
1982	723.4096805723077
1983	606.5102310236354
1984	512.123095588621
1985	451.641580437571
1986	449.5182422321273
1987	489.75594767382347
1988	502.0828279935901
1989	473.3689894760612
1990	519.8103352560574
1991	531.8502934956923
1992	514.5297510920356
1993	466.62386726610606
1994	442.1432526976632
1995	503.4595812141501
1996	510.08256378476966
1997	518.8893565116239
1998	495.3351477579694
1999	493.61676385195545
2000	487.0381825381714
2001	455.915451566865
2002	486.6442707149085
2003	599.7515977285601
2004	723.5277340949228
2005	820.6943861334343
2006	958.6042291598874
2007	1047.913079405342
2008	1115.9043615538346
2009	1116.4357311407916
2010	1253.0174745883057
2011	1353.9769400441673
2012	1399.9557892054238
2013	1470.1025341348732
2014	1544.103479338012
2015	1379.5406479514793
2016	1260.5706333214405
2017	1313.1901517712852
2018	1319.4315994580393
2019	1313.8986830575755
2020	1228.8056819274882
2021	1306.1862688282456