Year	%
2000	24.2
2001	24.5
2002	24.6
2003	24.5
2004	24.9
2005	25.7
2006	26.4
2007	26.6
2008	25.2
2009	24.4
2010	23.7
2011	23.7
2012	22.9
2013	22.2
2014	21.4
2015	22.2
2016	21.4
2017	19.8
2018	19.8
2019	19.3