Year	%
2000	15.2
2001	15
2002	14.9
2003	14.8
2004	14.7
2005	14.6
2006	14.6
2007	14.7
2008	14.7
2009	14.6
2010	14.7
2011	14.8
2012	15
2013	15
2014	15.2
2015	15.4
2016	15.6
2017	15.8
2018	15.9
2019	16.1