Year	%
2000	13
2001	12.6
2002	12.3
2003	12
2004	11.5
2005	11.3
2006	11
2007	10.8
2008	10.6
2009	10.2
2010	10
2011	9.7
2012	9.7
2013	9.5
2014	9.2
2015	9.3
2016	9.3
2017	8.9
2018	8.7
2019	8.5