Year	2017 PPP (% of population)
1981	58.9
1982	57.8
1983	56
1984	54.8
1985	53.6
1986	52.5
1987	52.1
1988	50.8
1989	50.4
1990	50
1991	48.5
1992	46.8
1993	46.2
1994	44.6
1995	43.8
1996	42.2
2002	40.4
2003	38.9
2004	37.2
2005	35.5
2006	33.8
2007	32.1
2008	30.9
2009	29.5
2010	25.4
2011	21.6
2012	19.9
2013	18.9
2014	17.9
2015	16.6
2016	15.8
2017	12.6
2018	10.1
2019	10.6
2020	13
2021	11.5
2022	9.7