Year	%
2000	27.3
2001	26
2002	25.2
2003	24.4
2004	23.7
2005	23.1
2006	22.4
2007	21.8
2008	21.2
2009	20.4
2010	19.6
2011	19
2012	18.3
2013	17.9
2014	17.6
2015	17.7
2016	17.4
2017	17.2
2018	17.1
2019	17.1