Year	%
2000	28.5
2001	28.1
2002	27.9
2003	27.9
2004	27.6
2005	27.6
2006	27.5
2007	26.6
2008	25.7
2009	25.8
2010	25.6
2011	25.1
2012	24.3
2013	23.8
2014	24.7
2015	24.3
2016	24.4
2017	24.5
2018	24.4
2019	24.2
