Year	%
2000	17.7
2001	17.1
2002	17.2
2003	16
2004	15.4
2005	14.8
2006	14.5
2007	14.4
2008	13.9
2009	13.5
2010	13.4
2011	12.8
2012	12.6
2013	12.4
2014	11.6
2015	11.2
2016	11
2017	10.7
2018	10.3
2019	10