Year	%
2000	16
2001	15.7
2002	16
2003	16.1
2004	15.7
2005	15.7
2006	15.3
2007	14.8
2008	15
2009	14.7
2010	14.5
2011	13.9
2012	13.9
2013	13.5
2014	13.8
2015	13.9
2016	14
2017	13.7
2018	13.6
2019	13.5