Year	%
2000	25.3
2001	23.6
2002	22.2
2003	22.6
2004	22
2005	20.8
2006	19.9
2007	20.5
2008	19.6
2009	18.5
2010	18.6
2011	17.4
2012	17
2013	16.9
2014	16.4
2015	16
2016	15.6
2017	15.1
2018	14.5
2019	14