Year	current US$
1960	1.0634729393720426
1961	3.234744974885738
1962	2.6731323768555644
1963	2.8084901739023516
1964	2.793345963556828
1965	3.1108653917388764
1966	3.2383810191318574
1967	2.625958296901858
1968	2.8254281474911456
1969	2.3348477004508332
1970	2.4667782039107196
1971	2.186947814521686
1972	2.132266333220629
1973	2.27005854737891
1974	2.6994531518403653
1975	2.927509587702772
1976	3.128232164389227
1977	2.9252319073105673
1978	3.677211881652021
1979	4.5341015375916935
1980	5.29025804659663
1981	5.577321940880037
1982	6.163492105127687
1983	6.603837543940725
1984	6.781310100531768
1985	7.840904699974595
1986	8.447380247838979
1987	9.938142886831345
1988	10.01958252485778
1989	10.856246548971443
1990	11.000822313869731
1991	12.818331900124734
1992	11.324654440177214
1993	10.914144576618448
1994	12.093432940519513
1995	12.912010309747256
1996	14.821533552597815
1997	10.12584578818766
1998	10.526748729198237
1999	11.62865593509476
2000	9.38586144937345
2001	11.223813808058503
2002	9.735938244705924
2003	11.285639195956264
2004	12.769614973065043
2005	12.024757620301598
2006	13.122838050264255
2007	12.262099256675494
2008	16.250328342499262
2009	15.34315962106329
2010	17.108225518794896
2011	17.678035228752925
2012	17.811330244922345
2013	18.264201439637358
2014	17.389067987615217
2015	17.858583146164577
2016	19.234931946821586
2017	14.36279771342552
2018	17.362059948481264
2019	14.058945025031218
2020	19.832071814622715
2021	19.194504843660027
2022	20.709073188339353