Year	2011 PPP (%)
1981	25.3
1984	17.6
1987	13.2
1990	14.7
1993	12.7
1996	8.7
1999	8.7
2002	6.7
2005	3.6
2008	2.8
2010	2
2011	1.5
2012	1.2
2013	0.7
2015	0.5