Year	current US$
1992	1.678395523341767
1993	7.711391119222696
1994	6.4311062116564885
1995	7.263482161276153
1996	5.496277199690497
1997	4.771210965174331
1998	6.212319773713042
1999	5.631982993737657
2000	7.776093748067884
2001	16.16579950809537
2002	9.387167695194265
2003	6.0601119718284435
2004	11.212102288963361
2005	5.945832388323347
2006	8.298296318077993
2007	5.725494002015505
2008	3.5528835195884847
2009	7.8441105358813825
2010	8.314398000949225
2011	7.614519462600751
2012	6.899101256935667
2013	6.458522713624875
2014	6.088482093052826
2015	3.979931566499191
2016	5.491976575217723
2017	4.714844772805029
2018	3.373417384818681
2019	4.113067949848516
2020	5.455617426190149
2021	4.527066463120443
2022	2.346530843520745