Year	2017 PPP (% of population)
1981	88.6
1982	88.5
1983	88.8
1984	88.6
1985	88.4
1986	87.6
1987	87.9
1988	87.8
1989	87.6
1990	87.6
1991	87.8
1992	87.9
1993	87.8
1994	87.3
1995	86.7
1996	86.3
1997	85.9
1998	85.6
1999	85.5
2000	84.5
2001	83.8
2002	82.6
2003	81.7
2004	80.1
2005	78.6
2006	77
2007	75.4
2008	74.2
2009	72.9
2010	70.8
2011	68.8
2012	67.1
2013	64.9
2014	63.4
2015	61.9
2016	60.8
2017	59.4
2018	57.5
2019	56.1
2020	57.1
2021	55.9
2022	54.9