Year	2017 PPP (%)
1981	30.8
1982	28.8
1983	26.6
1984	23
1985	20.9
1986	19.3
1987	18.1
1988	15.8
1989	19.6
1990	18.9
1991	18.3
1992	17.4
1993	16.5
1994	14.3
1995	12.7
1996	11.6
1997	11.8
1998	12.4
1999	11.3
2000	10.3
2001	9.5
2002	8.3
2003	7
2004	5.9
2005	4.7
2006	4.5
2007	4.1
2008	3.8
2009	3.3
2010	2.7
2011	2
2012	1.7
2013	0.8
2014	0.8
2015	0.6
2016	0.6
2017	0.6
2018	0.5
2019	0.5
2020	0.5
2021	0.5
2022	0.4