Year	current US$
2000	259.646698
2001	231.98364258
2002	227.21820068
2003	243.10256958
2004	253.98324585
2005	263.89520264
2006	271.49783325
2007	293.61825562
2008	336.35327148
2009	354.44778442
2010	370.31329346
2011	388.87130737
2012	408.77490234
2013	387.08288574
2014	394.67294312
2015	398.52124023
2016	421.32177734
2017	404.60903931
2018	484.5222168
2019	442.51159668
2020	420.02459717
2021	482.42965698