Year	2011 PPP (%)
1981	45.1
1984	46.5
1987	46.4
1990	47.3
1993	51
1996	50.4
1999	49.4
2002	47.5
2005	42.7
2008	39.2
2010	37.6
2011	36.7
2012	35.6
2013	34.9
2015	34.8