Year	Percent
1991	59.723
1992	60.094
1993	60.167
1994	60.501
1995	60.621
1996	60.941
1997	61.589
1998	61.275
1999	61.83
2000	62.442
2001	62.549
2002	62.531
2003	62.67
2004	62.879
2005	62.999
2006	63.083
2007	63.299
2008	62.657
2009	62.194
2010	61.973
2011	62.467
2012	63.192
2013	63.008
2014	63.36
2015	63.613
2016	63.71
2017	63.31
2018	63.607
2019	63.897
2020	64.105
2021	64.339
2022	64.557