Year	%
2000	21.4
2001	21.7
2002	22.7
2003	23.1
2004	24.5
2005	25.8
2006	27
2007	29.7
2008	32.1
2009	33.5
2010	33.3
2011	32.5
2012	32
2013	31.4
2014	31.2
2015	31.1
2016	30.4
2017	29.3
2018	28.5
2019	28.4