Year	Percent
1991	58.857
1992	60.141
1993	61.593
1994	54.567
1995	53.517
1996	53.066
1997	52.933
1998	53.129
1999	52.294
2000	49.975
2001	48.869
2002	48.554
2003	48.98
2004	50.282
2005	49.339
2006	49.165
2007	50.931
2008	49.757
2009	49.249
2010	48.841
2011	48.463
2012	47.957
2013	49.438
2014	48.799
2015	47.908
2016	46.48
2017	48.934
2018	48.742
2019	48.54
2020	48.332
2021	48.173
2022	47.948