Year	current US$
1960	0.5415055403560092
1961	3.8591525365970756
1962	2.31948220783828
1963	2.317696488758703
1964	2.862655084304139
1965	2.771680661360434
1966	3.689614381251383
1967	2.0226527954159614
1968	2.396593990844579
1969	1.4795684905900008
1970	1.4200496379549727
1971	1.2156982116693908
1972	0.9331544621451638
1973	0.6279728241341238
1974	1.2226920108618118
1975	1.2196814507369629
1976	0.831457503412066
1977	0.5929442263843744
1978	0.7652721186085476
1979	0.7347173182824438
1980	0.6799501267906937
1981	1.8146003451904025
1982	1.3874975257028934
1983	0.8147972525383812
1984	1.146922119188812
1985	0.6212021187159349
1986	1.0579809221367105
1987	2.0572589475490917
1988	1.5059829034762444
1989	1.5702340393795655
1990	1.1570839171856857
1991	1.2791479507017918
1992	-1.511089211485426
1993	1.2466480273632734
1994	1.6142951495209183
1995	1.6165456156640312
1996	1.552664757661657
1997	1.3633609186214064
1998	1.5236803320445982
1999	0.8322272173372199
2000	1.4537703113107574
2001	1.4141593863344106
2002	1.3099199138221596
2003	1.2555489763900727
2004	0.9651257418114253
2005	1.1629716593983295
2006	0.5836224918848774
2007	1.7223552702915603
2008	2.4322643344908395
2009	1.9268698350635396
2010	2.367057463787285
2011	4.241939205165709
2012	6.443418410945676
2013	5.729327070929088
2014	4.493028590258869
2015	4.88912119700745
2016	3.261294504249704
2017	1.3134939097716813
2018	2.117225183061935
2019	1.2866951406713814
2020	2.8731266280645467
2021	5.200203798965374
2022	2.6798599025390644