Year	2011 PPP (% of population)
1984	62.4
1987	61.9
1990	59.1
1993	60.5
1996	60.8
1999	54.4
2002	52.6
2005	49.6
2008	46.7
2010	42.9
2011	41.8
2012	41.5
2013	41.2
2015	42.1