Year	2017 PPP (% of population)
1981	97.6
1982	97.6
1983	97.5
1984	97.5
1985	97.5
1986	97.4
1987	97.2
1988	96.9
1989	96.5
1990	96.3
1991	96
1992	95.5
1993	95
1994	94.2
1995	93.3
1996	92.3
1997	91.6
1998	91.4
1999	90.7
2000	89.5
2001	87.8
2002	85.2
2003	83.1
2004	80.9
2005	78.2
2006	76
2007	72.9
2008	70.8
2009	67.7
2010	63.5
2011	60.2
2012	56.6
2013	51.2
2014	47.3
2015	43.6
2016	40.3
2017	38.1
2018	34.9
2019	32.3
2020	32.5
2021	29.6
2022	29.2