Year	2011 PPP (% of population)
1990	66.2
1993	56.6
1996	41.7
1999	40.2
2002	31.7
2005	18.5
2008	14.8
2010	11.2
2011	7.9
2012	6.5
2013	1.9
2014	1.4
2015	0.7