Year	Percent
1990	92.24
1991	92.27
1992	92.28
1993	92.28
1994	92.27
1995	92.25
1996	92.22
1997	92.19
1998	92.17
1999	92.14
2000	92.08
2001	92.03
2002	91.97
2003	91.9
2004	91.83
2005	91.76
2006	91.7
2007	91.65
2008	91.61
2009	91.57
2010	92.27
2011	92.71
2012	93.06
2013	93.03
2014	92.97
2015	92.36
2016	92.39
2017	93.15
2018	94.68
2019	94.65