Year	2017 PPP (% of population)
1981	87.6
1982	87.2
1983	86.4
1984	85.8
1985	85.1
1986	84.6
1987	84.5
1988	83.9
1989	83.7
1990	83.5
1991	82.9
1992	81.9
1993	81.6
1994	80.6
1995	80
1996	79.1
2002	77.4
2003	76.3
2004	75
2005	73.7
2006	72.5
2007	71.2
2008	70.1
2009	68.9
2010	65.8
2011	61.8
2012	59.9
2013	58.8
2014	58.1
2015	57
2016	55.8
2017	51.9
2018	45.9
2019	42.3
2020	45.1
2021	42.4
2022	39