Year	2011 PPP (%)
1981	38.9
1984	40.4
1987	40.3
1990	41.1
1993	41.8
1996	39.5
1999	39.1
2002	37.5
2005	33
2008	30.2
2010	28.7
2011	27.8
2012	26.8
2013	26
2015	25.2