Year	current US$
2000	15.96588552
2001	13.25978423
2002	13.13524191
2003	12.84223489
2004	16.96204948
2005	18.21469988
2006	20.28770509
2007	22.54030006
2008	24.75548082
2009	24.58196798
2010	24.43611772
2011	34.48942834
2012	48.34543504
2013	51.17153228
2014	55.41192221
2015	34.4740284
2016	39.14132841
2017	41.95551152
2018	41.74199862
2019	35.17793751
2020	38.6987838
2021	30.70726541