Year	current US$
2000	22.31892506
2001	20.12893927
2002	22.05039884
2003	27.25220937
2004	30.85197024
2005	31.67413243
2006	32.72969621
2007	36.46433594
2008	40.09177333
2009	38.84691541
2010	37.63426699
2011	40.19653562
2012	37.6737648
2013	39.47375378
2014	39.8667691
2015	35.19440268
2016	35.8544115
2017	38.00230661
2018	41.69515486
2019	40.56028247
2020	39.68438522
2021	42.68366892