Year	2017 PPP (%)
1981	40.7
1982	38
1983	34.8
1984	30.1
1985	27.6
1986	26
1987	24
1988	21
1989	26
1990	25
1991	24.2
1992	22.8
1993	21.5
1994	18.7
1995	16.5
1996	14.6
1997	14.7
1998	15.5
1999	13.9
2000	12.8
2001	11.8
2002	10.4
2003	8.6
2004	7.2
2005	5.7
2006	5.6
2007	4.9
2008	4.7
2009	3.9
2010	3.2
2011	2.4
2012	1.9
2013	0.8
2014	0.7
2015	0.5
2016	0.4
2017	0.4
2018	0.3
2019	0.2
2020	0.2
2021	0.2
2022	0.2