Year	%
2000	22.5
2001	22.7
2002	22.8
2003	23.2
2004	22.8
2005	22.8
2006	22.8
2007	23.3
2008	23.2
2009	23.4
2010	23.7
2011	23.7
2012	23.8
2013	23.7
2014	23.5
2015	23.2
2016	23.1
2017	23.2
2018	23
2019	22.6