Year	current US$
2000	0.6502687539040171
2001	0.6331697994624207
2002	0.7354960167024801
2003	0.9419031127356882
2004	1.6767798106589575
2005	1.3052971393412955
2006	1.699257780368525
2007	2.294107799797129
2008	2.427494562839333
2009	2.1327223689993153
2010	2.3576921636033465
2011	2.768549122632046
2012	2.8972723172412937
2013	3.4985067431025056
2014	3.68101644382535
2015	3.052176912156061
2016	3.029578260411182
2017	2.7997525035531363
2018	2.822284303887502
2019	3.209751956548548
2020	2.978218119844769
2021	5.4606849638430255