Year	Percent
1990	65.43
1991	65.52
1992	65.39
1993	65.23
1994	65.03
1995	64.95
1996	64.87
1997	64.88
1998	64.93
1999	64.88
2000	64.73
2001	64.54
2002	64.22
2003	63.84
2004	63.52
2005	63.3
2006	63.21
2007	63.26
2008	63.4
2009	63.62
2010	63.81
2011	63.84
2012	63.88
2013	63.9
2014	63.88
2015	63.84
2016	63.84
2017	63.82
2018	63.75
2019	63.7