Year 2017 PPP (% of population) 1980 1 1986 1.8 1987 2.1 1991 3 1992 4.1 1993 4.9 1994 4.4 1995 7.4 1996 8.3 1997 7.8 1998 8.3 1999 8.9 2000 10.7 2001 15.4 2002 24 2003 12.7 2004 9.8 2005 8 2006 6 2007 5 2008 4.8 2009 4.1 2010 3.1 2011 2.1 2012 2.3 2013 2.1 2014 2.1 2016 2.3 2017 2.4 2018 2.9 2019 3.4 2020 4 2021 2.8 2022 2.5