Year	%
2004	43.9
2005	42.4
2006	41.7
2007	41.4
2008	40.9
2009	40.9
2010	40.7
2011	40.6
2012	40.4
2013	40.5
2014	40.3
2015	39.3
2016	39.4
2017	38.2
2018	38.6
2019	37.6
2020	37.3
2021	37.3