Year 2011 PPP (%) 1990 1.1 1997 10 1999 15.3 2000 17.6 2001 12.3 2002 13.4 2004 6 2005 9.9 2006 8 2007 6 2008 5 2009 5 2011 3.1 2012 4 2013 3.1 2014 2.6 2015 2.8 2016 3 2017 2.5