Year	2017 PPP (% of population)
1981	52.6
1982	51.9
1983	50.8
1984	50
1985	49.2
1986	48.4
1987	48.2
1988	47.2
1989	46.9
1990	46.5
1991	45.6
1992	44.5
1993	44.2
1994	43
1995	42.2
1996	40.8
2002	38.5
2003	37.1
2004	35.1
2005	33.4
2006	31.7
2007	29.8
2008	28.5
2009	27
2010	23.8
2011	21.2
2012	19.8
2013	19
2014	18.1
2015	17.1
2016	16.5
2017	14.4
2018	12.7
2019	12.9
2020	14.8
2021	13.8
2022	12.6