Year	%
2000	38.2
2001	38.5
2002	38
2003	36.8
2004	36.7
2005	35.1
2006	35
2007	34.9
2008	32.8
2009	30.5
2010	29
2011	28.7
2012	27.8
2013	26.8
2014	26.7
2015	25
2016	25.2
2017	24.5
2018	24.4
2019	22.1