Year	%
2000	24.3
2001	24.2
2002	24.2
2003	24
2004	24
2005	23.9
2006	23.8
2007	23.7
2008	23.3
2009	23.2
2010	23
2011	22.7
2012	22.8
2013	22.8
2014	22.7
2015	22.7
2016	22.6
2017	22.4
2018	22.3
2019	22.1