Year	Percent
1990	90.11
1991	90.41
1992	90.69
1993	90.96
1994	91.2
1995	90.29
1996	89.25
1997	88.07
1998	86.72
1999	86.39
2000	86.04
2001	85.63
2002	85.21
2003	84.76
2004	84.76
2005	84.6
2006	84.48
2007	84.35
2008	84.2
2009	84.05
2010	83.88
2011	83.7
2012	83.51
2013	84.63
2014	84.64
2015	84.33
2016	86.02
2017	86.22
2018	85.65
2019	86.13