Year	%
2000	33.5
2001	31.5
2002	32.6
2003	33.2
2004	32
2005	32.5
2006	32.8
2007	32.1
2008	30.6
2009	29.5
2010	27.9
2011	28.4
2012	26.9
2013	26.2
2014	26.3
2015	24.9
2016	23
2017	22.3
2018	21.3
2019	20.3