Year	%
2000	21.9
2001	21.3
2002	20.7
2003	20.1
2004	19.6
2005	19.2
2006	18.7
2007	18.3
2008	17.8
2009	17.3
2010	16.9
2011	16.5
2012	16.1
2013	15.8
2014	15.5
2015	15.2
2016	15.1
2017	14.9
2018	14.8
2019	14.7