Year	%
2000	24.5
2001	24.5
2002	24.4
2003	24.3
2004	24.2
2005	24.1
2006	23.9
2007	23.8
2008	23.7
2009	23.5
2010	23.2
2011	22.9
2012	22.8
2013	22.5
2014	22.3
2015	22.1
2016	21.9
2017	21.6
2018	21.3
2019	21.1