Year 2011 PPP (% of population) 1981 68.6 1984 71 1987 70.7 1990 70.2 1993 74.5 1996 72.8 1999 68.4 2002 67.8 2005 65.5 2008 61.5 2010 58.6 2011 58.6 2012 57 2013 56.1 2015 56.4