Year	%
2000	15.4
2001	15.1
2002	15
2003	14.5
2004	13.7
2005	13.7
2006	13.4
2007	13.1
2008	13.2
2009	12.8
2010	12.9
2011	12.6
2012	12.2
2013	11.9
2014	11.5
2015	11.5
2016	11.1
2017	11
2018	10.8
2019	10.6