Year	current US$
1960	2.616196810074522
1961	3.4144907012700796
1962	3.8088238309281173
1963	3.687418330597625
1964	4.015272734053799
1965	4.21166364505518
1966	4.398740722406456
1967	4.721167100871794
1968	4.125659191446643
1969	3.9320373995582667
1970	3.977070228586197
1971	4.468916928036504
1972	4.664462280201919
1973	5.643390625345972
1974	7.917225014936353
1975	10.363281755995294
1976	9.29424010324172
1977	10.771460246369822
1978	14.172019927338637
1979	17.5777924994258
1980	19.80828836310639
1981	18.670641850522124
1982	19.01795070060315
1983	17.84082121138523
1984	19.16907522187364
1985	20.494207593687424
1986	23.799600990485377
1987	26.913780430914905
1988	29.620450167660316
1989	30.81196974349041
1990	34.470968971790526
1991	33.54415594150364
1992	35.27955539032954
1993	30.982477222657344
1994	33.4157208037121
1995	31.604976165359837
1996	26.989290608101282
1997	23.95970596419474
1998	22.684042894123664
1999	20.20976208825801
2000	19.421086483384165
2001	20.71568448422143
2002	26.83807141305325
2003	34.22303447639366
2004	35.47103196335021
2005	42.797795741401934
2006	52.261411708531725
2007	38.608616436507425
2008	43.43471120656146
2009	45.7140727014035
2010	50.367846432878295
2011	52.322236623186605
2012	50.28675320369138
2013	49.921500467801195
2014	47.32728586603151
2015	44.383631929661526
2016	42.766696895486135
2017	46.58358002888336
2018	46.59294529350846
2019	47.33114460888071
2020	58.1742354020984
2021	53.521886294898785
2022	49.324063601650785