Year	Percent
1990	63.73
1991	63.94
1992	64.14
1993	64.32
1994	64.5
1995	64.67
1996	64.91
1997	64.99
1998	64.91
1999	63.55
2000	63.91
2001	64.32
2002	64.04
2003	63.88
2004	63.81
2005	63.83
2006	63.64
2007	63.91
2008	64.2
2009	64.44
2010	64.66
2011	64.79
2012	64.92
2013	64.94
2014	65.02
2015	65.06
2016	65.1
2017	64.96
2018	64.88
2019	64.92