Year	Percent
1991	43.317
1992	44.774
1993	45.588
1994	46.311
1995	46.918
1996	53.522
1997	53.677
1998	53.038
1999	52.909
2000	53.25
2001	54.443
2002	53.618
2003	51.619
2004	53.221
2005	55.09
2006	56.851
2007	60.964
2008	62.116
2009	63.383
2010	63.941
2011	64.744
2012	64.426
2013	65.286
2014	65.62
2015	65.535
2016	65.13
2017	65.111
2018	64.993
2019	64.747
2020	64.4
2021	63.911
2022	63.334