Year	%
2000	27.6
2001	27.3
2002	27.7
2003	28
2004	27.9
2005	27.9
2006	28
2007	27.7
2008	27.8
2009	27.5
2010	26.9
2011	25.8
2012	24.6
2013	24.2
2014	24.5
2015	24.7
2016	24.5
2017	23.7
2018	21.4
2019	20.4