Year $ 2017 PPP (%) 1997 0.39 2002 0.03 2003 0.23 2004 0.02 2005 0.09 2006 0 2007 0 2008 0 2009 0.18 2010 0 2011 0 2012 0 2013 0 2014 0 2015 0 2016 0