Year	%
1982	43.5
1992	41.3
2000	41.3
2002	39.7
2006	41.4
2007	41.8
2008	41.3
2009	40.6
2010	40.4
2011	39.8
2012	39.8
2013	40.5
2014	40.5
2015	40.2
2016	40.8
2017	40.6
2018	40.8
2019	41.6
2020	41.5