Year	Percent
1991	96.762
1992	97.187
1993	96.277
1994	95.947
1995	94.489
1996	93.957
1997	94.981
1998	94.613
1999	93.594
2000	94.637
2001	94.389
2002	94.1
2003	94.091
2004	93.63
2005	93.736
2006	93.414
2007	93.166
2008	93.398
2009	93.305
2010	92.432
2011	92.215
2012	92.771
2013	92.137
2014	91.611
2015	91.126
2016	91.001
2017	90.976
2018	90.938
2019	90.902
2020	90.867
2021	90.833
2022	90.799