Year	%
2000	33.2
2001	34.5
2002	35.6
2003	34.5
2004	33.7
2005	34.1
2006	32.7
2007	30.8
2008	30.9
2009	30.7
2010	30.8
2011	30.7
2012	27.5
2013	26.4
2014	25.7
2015	24.7
2016	24.6
2017	24.2
2018	24.3
2019	23.8