Year	%
2000	15.1
2001	14.5
2002	14.1
2003	14.1
2004	13.8
2005	13.5
2006	13.2
2007	12.6
2008	12.1
2009	11.3
2010	11.1
2011	10.5
2012	10.3
2013	10.2
2014	10.2
2015	10.3
2016	10.3
2017	10.2
2018	9.8
2019	9.7