Year	%
2000	28.2
2001	27.8
2002	27.5
2003	27
2004	26.7
2005	26.5
2006	26.2
2007	26.2
2008	26.1
2009	26
2010	25.8
2011	25.6
2012	25.6
2013	25.6
2014	25.6
2015	25.4
2016	25.2
2017	24.7
2018	24.5
2019	24.3