Year	current US$
2000	2.67699855
2001	3.8777726
2002	4.8084618
2003	5.65674197
2004	7.98547349
2005	10.0638583
2006	11.07694083
2007	10.14873272
2008	14.63200335
2009	9.79097018
2010	10.24126164
2011	9.52736615
2012	9.75564048
2013	10.99192166
2014	11.79396511
2015	11.33689941
2016	14.73167747
2017	14.94065628
2018	15.33809599
2019	16.01981692
2020	8.8487546
2021	10.1001695