Year	%
1991	8.8
1992	8.9
1993	9
1994	8.5
1995	8.6
1996	9
1997	8.8
1998	9
1999	8.8
2000	8.8
2001	8.6
2002	8.6
2003	8.5
2004	8.5
2005	8.2
2006	8.3
2007	8.4
2008	8.4
2009	8.3
2010	8.4
2011	8.4
2012	8.2
2013	8.2
2014	8.1
2015	8
2016	7.9
2017	7.6
2018	7.9
2019	7.9