Year	%
2000	16.7
2001	17.2
2002	17.5
2003	17.3
2004	17.3
2005	16.2
2006	16.4
2007	15.3
2008	14.6
2009	14.1
2010	14
2011	13.6
2012	13.4
2013	12.9
2014	13.4
2015	12.9
2016	12.2
2017	11.5
2018	10.6
2019	10.7