Year	Percent
1991	98.104
1992	98.096
1993	98.032
1994	97.96
1995	97.812
1996	97.807
1997	98.08
1998	97.991
1999	97.836
2000	97.533
2001	96.977
2002	96.971
2003	96.854
2004	96.693
2005	96.422
2006	96.085
2007	94.805
2008	95.567
2009	93.213
2010	94.712
2011	95.856
2012	95.64
2013	95.525
2014	94.764
2015	93.961
2016	93.376
2017	93.174
2018	93.289
2019	93.274
2020	93.321
2021	93.376
2022	93.385