Year	2011 PPP (% of population)
1984	32.1
1987	30.8
1990	26.8
1993	29.6
1996	28.9
1999	21.5
2002	20.1
2005	18.9
2008	16.8
2010	13.7
2011	13.5
2012	13.2
2013	13.2
2015	15.6