Year	current US$
2003	1.06371969
2004	3.11387068
2005	2.57764766
2006	3.98231032
2007	4.72592656
2008	4.46317789
2009	3.55317223
2010	16.76805944
2011	14.54086966
2012	3.9451673
2013	1.40651719
2014	2.94854745
2015	2.27726131
2016	2.20003607
2017	0.36187542
2018	0.36744647
2019	0.33202559
2020	0.32947855
2021	0.33242291