Year	2017 PPP (% of population)
1985	7
1986	7.2
1987	7.5
1988	7.1
1989	7
1990	6.3
1991	6.1
1992	5.4
1993	5.2
1994	4.9
1995	4.9
1996	4.3
1997	4.2
1998	3.8
1999	3.7
2000	3.4
2001	3.3
2003	3.1
2004	2.8
2005	2.7
2006	2.7
2007	2.7
2008	2.6
2009	2.3
2010	2
2011	2.2
2012	2.3
2013	2.5
2014	2.8
2015	3.7
2016	4.5
2017	4.7
2018	4.7