Year	current US$
2000	9.79860488
2001	10.28986038
2002	12.11880532
2003	13.55467557
2004	14.23710841
2005	17.68839418
2006	20.74993873
2007	24.4908163
2008	27.04195253
2009	23.89649885
2010	24.60291991
2011	38.78161192
2012	35.37423471
2013	45.0454247
2014	38.41986024
2015	31.08621847
2016	31.47230892
2017	35.48745463
2018	36.73023402
2019	35.21514206
2020	33.5035589
2021	37.05257208
