Year	2017 PPP (% of population)
1981	68.6
1982	68.7
1983	69.1
1984	69.2
1985	69.1
1986	68.6
1987	69
1988	69
1989	69
1990	69.2
1991	69.6
1992	70
1993	70.5
1994	70.5
1995	69.8
1996	69.9
1997	69.4
1998	69.3
1999	69.8
2000	69
2001	68.3
2002	67.4
2003	66.8
2004	65.5
2005	64.2
2006	62.9
2007	61.5
2008	60.4
2009	59.4
2010	57.7
2011	56.3
2012	55
2013	53.2
2014	52.1
2015	50.9
2016	50
2017	48.9
2018	47.5
2019	46.4
2020	47.2
2021	46.3
2022	45.5