Year	%
2000	46.8
2001	45.9
2002	46.3
2003	46.3
2004	47.3
2005	48.4
2006	46.5
2007	47
2008	46.5
2009	42.8
2010	41.4
2011	39.8
2012	39.8
2013	38.7
2014	39.3
2015	37.5
2016	37.4
2017	36.2
2018	37.6
2019	36.9