Year	%
2000	18.1
2001	17.6
2002	17
2003	16.7
2004	15.8
2005	15.4
2006	14.8
2007	14.4
2008	14.1
2009	13.9
2010	13.5
2011	13.5
2012	13.3
2013	12.7
2014	12.4
2015	12.4
2016	11.8
2017	11.8
2018	11.5
2019	11.3