Year	2017 PPP (% of population)
1981	58.2
1982	57.2
1983	56
1984	54
1985	52
1986	50.1
1987	48.8
1988	46.4
1989	49.5
1990	48.9
1991	47.9
1992	46.5
1993	45.4
1994	43.1
1995	41.4
1996	39.3
1997	39
1998	39.3
1999	38
2000	36.6
2001	35.4
2002	33.6
2003	31.5
2004	29.1
2005	26.8
2006	25.6
2007	24.1
2008	23.1
2009	21.8
2010	19.6
2011	17.2
2012	16
2013	14.2
2014	13.5
2015	12.9
2016	12.6
2017	11.6
2018	10.7
2019	10.8
2020	11.8
2021	11.5
2022	10.8