Year	%
2004	37
2005	35.3
2006	34.4
2007	34.8
2008	35.7
2009	37.2
2010	33.6
2011	32.5
2012	35.1
2013	35.3
2014	37.7
2015	37.4
2016	38.4
2017	37.3
2018	35.7
2019	35.3
2020	36
2021	36.7