Year 2017 PPP (% of population) 2004 5 2005 2.8 2006 1.8 2007 1.3 2008 0.7 2009 0.9 2010 1.1 2011 0.9 2012 0.7 2013 0.9 2014 1.1 2015 0.9 2016 0.6 2017 0.6 2018 0.4 2019 0.2 2020 0.3 2021 0.2