Year	2011 PPP (% of population)
1990	90
1993	83.4
1996	72.9
1999	68.3
2002	57.7
2005	43.2
2008	34.6
2010	28.5
2011	23.5
2012	20.2
2013	12.1
2014	9.5
2015	7