Year	%
2000	34.4
2001	33.4
2002	31.4
2003	31
2004	29.2
2005	29.9
2006	30.4
2007	30.1
2008	31.6
2009	30.5
2010	30.2
2011	30.1
2012	28
2013	27.4
2014	29.3
2015	28.9
2016	28.3
2017	27.3
2018	26.8
2019	26