Year	2011 PPP (% of population)
1992	8.9
1996	16.5
1999	20.1
2000	16.4
2001	19.7
2002	14.3
2003	12
2004	10.9
2005	9.7
2008	10.4
2009	8.9
2010	7.7
2011	6.3
2012	6.2
2013	5.7
2014	5
2015	4.5
2016	4.5
2017	3.9