Year	%
2000	28
2001	27.9
2002	27.5
2003	27.9
2004	27.8
2005	27.5
2006	27.3
2007	26.8
2008	26.8
2009	27
2010	26.7
2011	26.3
2012	25.9
2013	25.3
2014	24.8
2015	24.3
2016	23.9
2017	23.7
2018	24.1
2019	24