Year	current US$
2000	1.6664044066041732
2001	1.4807350467005278
2002	1.7517661573282475
2003	2.141586661379774
2004	2.7735504096937333
2005	3.3021623528179584
2006	4.276839589974391
2007	4.664546571534093
2008	5.5058672607149
2009	5.952115967620271
2010	6.571159998157837
2011	7.772265445181523
2012	7.77566536212462
2013	9.035808318472132
2014	9.369835491129127
2015	8.111202489439625
2016	7.792438573816633
2017	7.825747860405305
2018	8.10196399054715
2019	8.568745181347797
2020	8.020892913822518
2021	9.994710723053112