Year	current US$
2000	0.82999617
2001	0.89613854
2002	1.01562262
2003	1.2617128
2004	1.43681598
2005	1.96962535
2006	2.08211623
2007	2.73076998
2008	3.05233238
2009	2.91884418
2010	2.87300786
2011	2.6499887
2012	2.97282186
2013	2.89577974
2014	3.2999404
2015	6.3170693
2016	3.31077011
2017	4.15362193
2018	3.55305389
2019	4.76065826
2020	5.48542464
2021	4.90858022