Year	current US$
2000	155.13145447
2001	161.76152039
2002	166.12776184
2003	170.78582764
2004	184.88005066
2005	223.97184753
2006	230.50076294
2007	238.63465881
2008	251.8334198
2009	255.38142395
2010	268.66708374
2011	293.3677063
2012	298.72540283
2013	321.82662964
2014	312.86746216
2015	329.44250488
2016	337.27490234
2017	335.73712158
2018	345.05181885
2019	377.02557373
2020	354.48699951
2021	442.21374512