Year	%
2000	20.8
2001	18.8
2002	17.9
2003	17.4
2004	17.6
2005	17.1
2006	17.3
2007	16.7
2008	15.6
2009	16
2010	15.9
2011	15.7
2012	15.8
2013	15.5
2014	14.9
2015	14.3
2016	14
2017	14.1
2018	13.9
2019	14.3