Year	2017 PPP (%)
1981	62.2
1982	62
1983	61.6
1984	61.2
1985	60.8
1986	60.4
1987	60.3
1988	59.8
1989	59.6
1990	59.4
1991	59
1992	58.6
1993	58.5
1994	58
1995	57.6
1996	56.8
2002	55.3
2003	54.6
2004	53.4
2005	52.5
2006	51.5
2007	50.4
2008	49.5
2009	48.2
2010	46.3
2011	44.4
2012	43.3
2013	42.5
2014	41.9
2015	41.2
2016	40.7
2017	38.9
2018	36.8
2019	35.5
2020	37
2021	36.1
2022	34.6