Year	current US$
1960	0.21396240379810388
1961	2.262327513833711
1962	0.9598461709704215
1963	0.07653421318949487
1964	-0.5499120973414664
1965	1.1453510007744516
1966	0.8198198949617247
1967	0.7889267724128672
1968	0.5749376104570421
1969	0.44483772242540676
1970	0.5951563599858746
1971	0.32409929143885924
1972	0.3959402374352572
1973	0.2391893873162413
1974	0.38738534668254143
1975	0.36836441604025233
1976	0.3386127083744765
1977	0.2972896806654631
1978	0.2707254915870512
1979	1.018448335908021
1980	0.9953447198217341
1981	1.6086081164609427
1982	2.124070690156598
1983	2.0776824420821165
1984	1.2722879332102992
1985	2.0159737998926595
1986	3.534302895097702
1987	2.2758481679950915
1988	2.2590372577085653
1989	1.4273294975044228
1990	2.1823184325208254
1991	3.4818769961235057
1992	3.990791570500964
1993	5.1519677399654835
1994	5.0979215039742884
1995	4.563320558628355
1996	3.3348780579833033
1997	1.2212516044139723
1998	0.31698704075477463
1999	0.4769823157687185
2000	-0.41339099001415214
2001	0.9954294601054571
2002	1.3431819639309426
2003	1.128973380680522
2004	1.3077005100319046
2005	1.8967701437605717
2006	2.300564867711754
2007	1.0383833053638611
2008	1.3520599348533047
2009	1.679882610937519
2010	4.040880732530785
2011	8.471449362804261
2012	3.5240532962838294
2013	4.794839503696295
2014	6.861891525836003
2015	2.6722453813191285
2016	6.6601811647185345
2017	6.143068573009152
2018	4.428618039500084
2019	4.197455111474632
2020	6.3015927804675895
2021	4.448596024137009
2022	3.8859920099551917