Year	Percent
1991	61.025
1992	62.101
1993	63.272
1994	64.062
1995	64.518
1996	65.02
1997	65.227
1998	65.534
1999	65.477
2000	65.652
2001	65.979
2002	66.194
2003	66.522
2004	66.308
2005	66.202
2006	66.176
2007	66.345
2008	67.156
2009	68.204
2010	67.118
2011	66.516
2012	66.009
2013	65.913
2014	66.182
2015	66.026
2016	65.797
2017	65.731
2018	65.663
2019	65.536
2020	65.322
2021	65.033
2022	64.672