Year	%
2000	36.9
2001	37.5
2002	38.4
2003	38.3
2004	37.4
2005	37.3
2006	34.6
2007	32.8
2008	32.8
2009	31.6
2010	30.9
2011	29.1
2012	27.7
2013	26.8
2014	28.4
2015	26.4
2016	27
2017	25.4
2018	25.3
2019	24.2