Year	current US$
2000	4.2405166
2001	0.74975297
2002	0.61430767
2003	1.16609458
2004	1.41385924
2005	1.65875732
2006	2.11539336
2007	2.82413134
2008	6.07406209
2009	5.42169518
2010	5.61396086
2011	5.5316197
2012	5.12827072
2013	6.36979892
2014	7.55280254
2015	7.51414859
2016	8.60691083
2017	7.9634311
2018	6.29625293
2019	7.71007027
2020	7.96603222
2021	8.37207039