Year	%
2000	26.2
2001	26.2
2002	25.1
2003	25.3
2004	24
2005	24
2006	24.7
2007	23.6
2008	23.8
2009	22.4
2010	21.7
2011	21.4
2012	18.5
2013	17.5
2014	19.3
2015	19.2
2016	18.6
2017	17.9
2018	17.6
2019	16.6