Year	current US$
2000	5.89315732
2001	5.94571153
2002	6.16840366
2003	6.13723704
2004	15.13100034
2005	10.56389909
2006	5.9553154
2007	4.99187408
2008	8.69006034
2009	8.32298093
2010	8.1021527
2011	6.91559812
2012	10.37592532
2013	7.9305522
2014	7.27439871
2015	4.32545394
2016	5.43741538
2017	4.31693331
2018	17.8390473
2019	21.16817999
2020	13.05754627
2021	24.32468625