Year 2017 PPP (% of population) 2004 2.5 2005 2.4 2006 1.6 2007 0.6 2008 1.3 2009 1.7 2010 1.7 2011 1 2012 1.1 2013 1.2 2014 0.8 2015 0.7 2016 0.6 2017 0.8 2018 0.4 2019 0.2 2020 0.5 2021 0.4