Year	%
2000	28.8
2001	28.5
2002	28.1
2003	27.6
2004	25.9
2005	26
2006	26.4
2007	26.9
2008	27.4
2009	27.5
2010	28
2011	28
2012	27.5
2013	26
2014	24.9
2015	25.4
2016	25.4
2017	25
2018	24.7
2019	24.6