Year	current US$
2000	0
2001	0
2002	0
2003	1
2004	1
2005	1
2006	1
2007	1
2008	1
2009	1
2010	1
2011	2
2012	2
2013	2
2014	2
2015	2
2016	1
2017	1
2018	1
2019	0
2020	0
2021	0
