Year	2017 PPP (% of population)
1981	58
1982	58.1
1983	58.2
1984	58
1985	57.6
1986	56.8
1987	56.8
1988	56.1
1989	56.6
1990	56.6
1991	56.5
1992	56.1
1993	55.8
1994	55.1
1995	54.1
1996	53.2
1997	52.6
1998	52.6
1999	52.4
2000	51.2
2001	50.3
2002	48.8
2003	47.5
2004	45.7
2005	43.9
2006	42.5
2007	40.8
2008	39.7
2009	38.3
2010	36.2
2011	34
2012	32.6
2013	30.5
2014	29.6
2015	28.6
2016	27.9
2017	26.6
2018	24.7
2019	23.4
2020	24.3
2021	23.7
2022	22.7