Year	%
2000	26.6
2001	26.6
2002	26.8
2003	27.2
2004	27.2
2005	27.6
2006	27.9
2007	28
2008	28.1
2009	27.9
2010	27.6
2011	26.9
2012	26.2
2013	25.7
2014	25.2
2015	24.6
2016	24
2017	23.4
2018	22.9
2019	22.4