Year	2017 PPP (%)
1981	25.4
1982	24.2
1983	22.8
1984	20.7
1985	19.4
1986	18.4
1987	17.6
1988	16.3
1989	18.2
1990	17.8
1991	17.4
1992	16.7
1993	16.2
1994	15
1995	14
1996	13.1
1997	13.1
1998	13.3
1999	12.7
2000	12.1
2001	11.6
2002	10.8
2003	9.9
2004	8.9
2005	8
2006	7.6
2007	7
2008	6.7
2009	6.2
2010	5.5
2011	4.8
2012	4.4
2013	3.9
2014	3.7
2015	3.7
2016	3.7
2017	3.4
2018	3.3
2019	3.3
2020	3.7
2021	3.6
2022	3.4