Year	%
2000	24.4
2001	24.3
2002	24.3
2003	24.3
2004	24.3
2005	24.4
2006	24.4
2007	24.5
2008	24.4
2009	24.2
2010	24
2011	23.8
2012	23.6
2013	23.4
2014	23.1
2015	22.9
2016	22.7
2017	22.6
2018	22.4
2019	22.3