Year	%
2000	27.1
2001	27.9
2002	28.1
2003	27.8
2004	27.3
2005	26.9
2006	26.3
2007	25.8
2008	25.1
2009	25
2010	25
2011	24.8
2012	24.8
2013	24.8
2014	24.7
2015	25
2016	25.5
2017	26.3
2018	27.5
2019	27.8