Year	Percent
1991	97.623
1992	97.452
1993	97.359
1994	97.438
1995	97.471
1996	97.58
1997	97.597
1998	97.479
1999	97.326
2000	96.231
2001	98.123
2002	98.175
2003	98.393
2004	98.526
2005	98.617
2006	98.567
2007	98.202
2008	98.678
2009	98.405
2010	98.268
2011	98.281
2012	98.15
2013	97.897
2014	98.057
2015	97.895
2016	97.911
2017	97.834
2018	97.814
2019	97.841
2020	97.883
2021	97.908
2022	97.931