Year	2011 PPP (%)
1981	38.1
1984	27.2
1987	21.6
1990	22.4
1993	19.3
1996	12.9
1999	12.3
2002	9.1
2005	4.9
2008	3.8
2010	2.5
2011	1.8
2012	1.5
2013	0.7
2015	0.5