Year	current US$
1970	2.539615149945096
1971	2.8002865358777815
1972	3.486572359165496
1973	5.05159886681135
1974	8.434803463987535
1975	9.94838034874447
1976	9.399473024445085
1977	11.188986576061891
1978	12.495693714296964
1979	17.075266906858847
1980	18.531531194310656
1981	18.087630295516703
1982	15.976513065361098
1983	14.331854657784472
1984	13.39654258836247
1985	15.281232024077246
1986	16.146858379790775
1987	18.49291911777501
1988	17.768882384734468
1989	16.894984924195278
1990	21.375789234523246
1991	20.000604737356298
1992	19.194318053974225
1993	17.72813272675973
1994	20.62317276288978
1995	16.949061366310143
1996	15.157387635568352
1997	13.534099900294692
1998	13.00775359960018
1999	11.809881736980426
2000	11.099086059064827
2001	13.659896605730676
2002	18.71841268872192
2003	29.964173288845448
2004	30.646712717336953
2005	68.50523982952983
2006	59.10888013748509
2007	50.047451495428376
2008	53.113903660857915
2009	47.05471722096309
2010	49.5032650981798
2011	50.22222850094973
2012	46.22057553224108
2013	53.01932376456957
2014	49.24675446814456
2015	46.88335616877164
2016	53.00320012952306
2017	58.22984201055377
2018	63.06238934256702
2019	58.719025442955164
2020	65.45611856471433
2021	61.9537812792505