Year	%
2000	13.2
2001	12.9
2002	12.7
2003	12.3
2004	12
2005	11.8
2006	11.4
2007	11.2
2008	11.1
2009	10.6
2010	10.4
2011	10.1
2012	9.8
2013	9.8
2014	9.1
2015	9.2
2016	9.1
2017	9
2018	8.5
2019	8.4