Year	2011 PPP (% of population)
1981	66.2
1984	66.8
1987	66.6
1990	67.1
1993	68.1
1996	67.4
1999	66.9
2002	64.1
2005	60.4
2008	56.6
2010	53.9
2011	52.2
2012	50.7
2013	48.7
2015	46.1