Year	%
2000	16.4
2001	16
2002	16.4
2003	16.2
2004	16
2005	15.9
2006	15.8
2007	16.7
2008	15.8
2009	15.8
2010	16
2011	15.9
2012	15.2
2013	16
2014	17.1
2015	17.6
2016	17.8
2017	18.2
2018	17.7
2019	17.6