Year	Percent
1990	76.64
1991	76.68
1992	76.72
1993	76.77
1994	76.88
1995	77.04
1996	77.19
1997	77.39
1998	77.6
1999	77.78
2000	77.94
2001	78.03
2002	78.12
2003	78.21
2004	78.29
2005	78.39
2006	78.45
2007	78.52
2008	78.59
2009	78.67
2010	78.77
2011	78.82
2012	78.87
2013	78.93
2014	79
2015	79.06
2016	79.06
2017	79.06
2018	79.06
2019	79.07