Year	2011 PPP (%)
1981	17.9
1984	14.6
1987	12.5
1990	12.7
1993	12
1996	9.8
1999	9.5
2002	8.2
2005	6.3
2008	5.4
2010	4.7
2011	4.1
2012	3.8
2013	3.4
2015	3.1