Year	current US$
2000	4.18430197
2001	4.64392063
2002	3.7429644
2003	6.27312144
2004	26.51378511
2005	5.71275157
2006	9.9824406
2007	7.19004525
2008	4.03643178
2009	12.87870256
2010	14.4273948
2011	12.67807419
2012	21.09200914
2013	20.31732444
2014	18.05700659
2015	2.42894438
2016	13.17443305
2017	13.32685707
2018	9.37014876
2019	10.03543668
2020	14.0535538
2021	24.93290289