Year	current US$
1960	1.815924239002462
1961	0.6475268852310739
1962	1.0107341633306575
1963	0.7073896250507131
1964	2.292849171355784
1965	2.8165976587818466
1966	1.350551533784266
1967	2.4976270689298192
1968	1.8345772575062218
1969	2.2096011964228883
1970	1.2279760017835195
1971	1.856240465876387
1972	4.134731203126476
1973	5.479600094928644
1974	3.699352518124483
1975	4.158564947708064
1976	4.20661656242087
1977	4.010167003082593
1978	5.393462818431318
1979	5.651030457259976
1980	6.020915577756491
1981	7.488627539447432
1982	6.369246489747112
1983	7.954471668735899
1984	7.028315113110486
1985	8.300819377026675
1986	15.845884020402321
1987	12.113522252610046
1988	13.243940923956398
1989	12.858542982916491
1990	18.569045303902453
1991	15.06541437168946
1992	25.354207895708825
1993	21.035413244747645
1994	14.912280667387895
1995	12.383598726354007
1996	12.134898151051853
1997	8.675056599921545
1998	7.956835944311771
1999	8.689286832333693
2000	7.090977276290264
2001	6.947220696943223
2002	6.8053896782048975
2003	8.738186994149356
2004	5.496084912915996
2005	6.813720062781666
2006	6.7690283117027645
2007	7.18233720061746
2008	0.962057678568405
2009	3.7156677183694065
2010	6.154589204896525
2011	-1.4103481265697337
2012	-0.03437641778434228
2013	1.9263770454989986
2014	6.6857997394094095
2015	4.997992720052102
2016	2.7046414728186146
2017	1.5034874410269168
2018	5.041962726892116
2019	8.029204240360942
2020	12.981079444129987
2021	14.347166135239442
2022	13.953736661663047