Year	Percent
1990	81.43
1991	81.61
1992	81.94
1993	82.35
1994	83.77
1995	83.58
1996	83.28
1997	83.15
1998	82.83
1999	82.55
2000	81.37
2001	86.06
2002	85.27
2003	84.2
2004	82.68
2005	83.18
2006	83.7
2007	84.15
2008	84.53
2009	84.88
2010	87.52
2011	87.98
2012	85.67
2013	83.08
2014	83.15
2015	83.18
2016	84.78
2017	84.94
2018	84.94
2019	84.9