Year	%
2000	30.6
2001	30.3
2002	30
2003	29.7
2004	29.5
2005	29.2
2006	28.7
2007	28.3
2008	27.9
2009	27.5
2010	27.3
2011	27.1
2012	27
2013	27
2014	27
2015	27.1
2016	27.2
2017	27.3
2018	27.4
2019	27.5