Year	%
1979	9.5
1986	10.2
1991	10
1995	9.7
2000	9.7
2003	9.5
2004	8.8
2005	9
2006	9.2
2007	9.4
2008	9.1
2009	9.4
2010	9.5
2011	9.5
2012	9.4
2013	9.3
2014	9.1
2015	9
2016	8.6
2017	8.9
2018	8.9
2019	8.8