Year	%
2000	16.8
2001	16
2002	16.1
2003	16.7
2004	17.4
2005	17.2
2006	17.5
2007	17.3
2008	16.9
2009	17.3
2010	17.3
2011	16.5
2012	16.2
2013	16.1
2014	15.8
2015	16
2016	16.3
2017	16.5
2018	16.2
2019	16