Year	%
2000	24
2001	23.5
2002	23.1
2003	22.5
2004	22.1
2005	21.6
2006	21.1
2007	20.6
2008	20
2009	19.5
2010	18.7
2011	18.3
2012	18.3
2013	18.2
2014	18.2
2015	18.3
2016	18.1
2017	17.9
2018	17.7
2019	17.6