Year	Percent
1991	59.025
1992	58.592
1993	58.341
1994	59.175
1995	60.091
1996	61.865
1997	63.076
1998	64.15
1999	63.768
2000	65.446
2001	65.629
2002	65.822
2003	65.987
2004	66.17
2005	66.347
2006	66.11
2007	65.852
2008	66.09
2009	63.56
2010	61.242
2011	63.062
2012	64.056
2013	64.126
2014	64.178
2015	64.226
2016	64.258
2017	64.276
2018	64.303
2019	64.344
2020	64.394
2021	64.454
2022	64.523