Year	%
2000	24.6
2001	23.7
2002	22.4
2003	21.3
2004	19.7
2005	18.3
2006	17.2
2007	16.2
2008	15.4
2009	14.7
2010	14
2011	13.2
2012	12.3
2013	11.4
2014	10.5
2015	9.9
2016	9.4
2017	9.4
2018	9.2
2019	9.3