Year	%
2000	15.8
2001	15.5
2002	15.1
2003	14.6
2004	14.2
2005	13.9
2006	13.4
2007	13.1
2008	12.9
2009	12.3
2010	12.1
2011	12
2012	11.3
2013	11.3
2014	10.5
2015	10.6
2016	10.7
2017	10.3
2018	9.8
2019	9.6