Year	2011 PPP (%)
1981	58.7
1984	49.9
1987	43.5
1990	44
1993	39.4
1996	31.1
1999	29.5
2002	23.5
2005	16
2008	13.1
2010	10.1
2011	8.2
2012	7.2
2013	4.6
2015	3.1