Year	2011 PPP (% of population)
1981	93.6
1984	90.9
1987	86.5
1990	85.2
1993	79.6
1996	70.5
1999	67
2002	57.1
2005	45.2
2008	37.6
2010	30.6
2011	26.5
2012	23.7
2013	17.5
2015	12.4