Year	%
2000	17
2001	17
2002	17.1
2003	16.8
2004	16.7
2005	16.2
2006	16.1
2007	16.5
2008	15.5
2009	15.4
2010	15.2
2011	14.6
2012	14.2
2013	14.1
2014	14
2015	14.1
2016	13.7
2017	13.6
2018	13.7
2019	13.6