Year 2017 PPP (% of population) 1987 15.4 1990 10.7 1992 6.7 1994 6.8 1996 4.7 1998 4.6 2000 5.8 2003 5.3 2006 2 2009 1.7 2011 0.9 2013 0.5 2015 0.4 2017 0.4 2020 1.3 2022 0.4