Year	%
2000	19.1
2001	18.5
2002	19.5
2003	19.7
2004	18.8
2005	19.8
2006	20.5
2007	20.6
2008	20.9
2009	20.5
2014	17.8
2015	17.4
2016	17
2017	17.3
2019	17