Year 2017 PPP (%) 1981 18.3 1988 15.2 1990 12.8 1992 10.1 1994 6.1 1996 4.6 1998 4.1 1999 5.7 2000 5.7 2002 3.5 2004 2.5 2006 1.8 2007 1.2 2008 0.9 2009 0.8 2010 0.6 2011 0.3 2012 0.4 2013 0.3 2014 0.2 2015 0.1 2016 0.1 2017 0.1 2018 0.1 2019 0.1 2020 0.1 2021 0.1