Year	current US$
1978	2.8617062156373474
1985	0.2851157245808005
1986	0.2768566414004103
1987	0.8239593942014408
1988	0.4475809419367218
1989	0.4054654604004788
1990	0.37164313907936686
1991	0.40823025766523735
1992	0.4939367816240175
1993	0.6457534304785
1994	0.25604805413254605
1995	0.6021745265441176
1996	1.1306981225159498
1997	3.8738579469996743
1998	4.571823587561496
1999	8.659096726668293
2000	3.14759350125139
2001	5.013924043947646
2002	11.185184735830338
2003	5.514322390299737
2004	6.716375474959256
2005	3.628482729385973
2006	2.276800811213471
2007	4.088435419721314
2008	8.428198929346902
2009	2.653213894261052
2010	3.1932517526752933
2011	4.780947653475019
2012	3.9324536809277006
2013	4.363682437430692
2014	6.110371659659698
2015	5.20349650104258
2016	4.7125574915613715
2017	5.217052846967555
2018	4.700417418442728
2019	5.205113651852981
2020	4.828845578970256
2021	0.7750681384555368
2022	0.4921475772110162