Year	2011 PPP (% of population)
1981	90.9
1984	90.9
1987	90.5
1990	89.9
1993	90.7
1996	89.9
1999	89.9
2002	88.5
2005	86.4
2008	84.5
2010	81.6
2011	79.6
2012	78.3
2013	77.1
2015	74.4