Year	%
2000	23.5
2001	19.6
2002	20.2
2003	21.2
2004	20.6
2005	25.2
2006	25.1
2007	24.9
2008	24.3
2009	23.2
2010	21.8
2011	18.8
2012	18.1
2013	17.5
2014	17.3
2015	17
2016	16.9
2017	16.9
2018	16.8
2019	16.7