Year 2017 PPP (%) 1993 55.9 1994 57 1995 57.3 1996 57.2 1997 56.7 1998 56.1 1999 57 2001 54.3 2002 54.1 2003 53.9 2004 51.6 2005 50.2 2006 49.2 2007 48.2 2008 47.4 2009 47.1 2010 46 2011 45.7 2012 45.4 2013 45 2014 44.7 2015 46.2 2016 46.3 2017 46.1 2018 45.9