Year	2011 PPP (% of population)
1999	16.9
2001	19.3
2002	15.1
2003	11.4
2004	7.9
2005	4.5
2006	3.2
2007	2.8
2008	1.4
2009	1.9
2010	1.9
2011	2.2
2012	1.6
2013	2.2
2014	2.3
2015	1.9
2016	1.8
2017	1.4