Year	%
2000	30.1
2001	29.2
2002	31.6
2003	31.6
2004	32.7
2005	32.9
2006	30.8
2007	31.5
2008	31.1
2009	27.8
2010	26.8
2011	25
2012	24.6
2013	23.8
2014	23.8
2015	23.3
2016	22.7
2017	22
2018	22
2019	22.3