Year	2017 PPP (% of population)
1993	66
1994	67.5
1995	68.2
1996	68.1
1997	67.7
1998	67.3
1999	69.1
2001	65.7
2002	65.5
2003	65.1
2004	62.6
2005	60.9
2006	59.8
2007	58.8
2008	58
2009	57.5
2010	56.3
2011	56
2012	55.7
2013	55.2
2014	54.6
2015	56.6
2016	56.5
2017	55.9
2018	55.5