Year	Percent
1990	76.41
1991	76.86
1992	77.17
1993	77.69
1994	78.37
1995	78.75
1996	78.55
1997	78.2
1998	78.01
1999	77.68
2000	77.17
2001	76.67
2002	76.44
2003	76.47
2004	76.11
2005	76.38
2006	76.55
2007	76.7
2008	76.87
2009	76.42
2010	76.68
2011	76.82
2012	77.03
2013	77.26
2014	77.54
2015	77.59
2016	77.01
2017	76.38
2018	76.56
2019	76.59