Year	%
2000	27
2001	26.9
2002	26.2
2003	25.5
2004	24.8
2005	23.7
2006	24
2007	23.3
2008	22
2009	20.7
2010	19.9
2011	19.1
2012	18.8
2013	18.2
2014	18
2015	17.1
2016	17.2
2017	16.9
2018	16.6
2019	14.9
