Year	Percent
1990	74.75
1991	75.03
1992	75.82
1993	76.07
1994	76.52
1995	76.59
1996	76.84
1997	76.88
1998	77.04
1999	76.95
2000	76.94
2001	76.74
2002	76.71
2003	77.1
2004	77.84
2005	78.36
2006	79.09
2007	79.49
2008	79.87
2009	80.09
2010	80.6
2011	81.45
2012	82.18
2013	82.55
2014	82.96
2015	83.54
2016	84.12
2017	84.78
2018	85.6
2019	86.31