Year	current US$
1960	1.45079484271979
1961	2.477108937809352
1962	2.742092936178778
1963	3.2238622908683254
1964	3.665630450816596
1965	3.9195473702767347
1966	4.623563478726986
1967	4.808740612612137
1968	3.874237094528846
1969	2.9331151621355516
1970	3.094513133691827
1971	3.423113126350697
1972	2.932519877527821
1973	4.383639454195609
1974	4.071697087383396
1975	5.467375245204556
1976	6.218213035678511
1977	4.314832137793334
1978	4.042673452494412
1979	7.3373397843500205
1980	4.061041098438737
1981	4.089743513148609
1982	4.668358231954842
1983	5.509401862040607
1984	7.575103352686634
1985	8.55060925156049
1986	10.113702048634028
1987	19.70938264764729
1988	15.013357623630611
1989	13.711798561926155
1990	13.847105648465329
1991	18.50784532008728
1992	20.278129519833755
1993	16.68129517788039
1994	16.922443407613926
1995	16.227740815691625
1996	20.24845161511457
1997	13.18836691849823
1998	14.841356873373291
1999	12.337208940638233
2000	12.289226004384666
2001	13.331495079101892
2002	17.86603855049608
2003	15.249018570907296
2004	13.620653838908638
2005	18.72184191219071
2006	15.266547495023971
2007	16.221068562453958
2008	17.21414758389443
2009	15.240695161369718
2010	11.243139738644999
2011	11.898099444468231
2012	9.562200745032369
2013	9.57324362896018
2014	10.342778863794411
2015	19.644475723680532
2016	14.824583875679767
2017	12.643631110600358
2018	23.747518556555747
2019	29.22380098545735
2020	19.5439146788018
2021	16.89990130651425
2022	20.897727497126883