Year 2017 PPP (% of population) 2004 0.5 2005 0.5 2006 0.4 2007 0.2 2008 0.1 2009 0.2 2010 0.1 2011 0.3 2012 0.3 2013 0.4 2014 0.3 2015 0.3 2016 0.2 2017 0.1 2018 0.1 2019 0.1 2020 0 2021 0.1