Year	Percent
1990	64.73
1991	64.8
1992	64.9
1993	65.02
1994	65.16
1995	65.31
1996	65.42
1997	65.54
1998	65.67
1999	65.81
2000	65.94
2001	66.02
2002	66.1
2003	66.16
2004	66.21
2005	66.25
2006	66.22
2007	66.32
2008	66.4
2009	66.48
2010	66.57
2011	66.69
2012	66.83
2013	66.97
2014	67.1
2015	67.24
2016	67.38
2017	70.6
2018	70.76
2019	70.89