Year	Percent
1990	90.7
1991	90.67
1992	90.65
1993	90.66
1994	91.08
1995	91.04
1996	91.03
1997	91.33
1998	91.59
1999	91.83
2000	91.65
2001	94.03
2002	92.39
2003	90.32
2004	87.74
2005	88.34
2006	88.89
2007	89.34
2008	90.21
2009	90.98
2010	93.18
2011	93.81
2012	92.5
2013	90.91
2014	90.6
2015	90.6
2016	92.28
2017	92.61
2018	92.63
2019	92.63