Year	Percent
1991	92.247
1992	92.605
1993	92.579
1994	93.509
1995	93.242
1996	93.312
1997	93.12
1998	93.277
1999	92.387
2000	92.424
2001	92.68
2002	92.842
2003	92.585
2004	92.24
2005	92.431
2006	92.018
2007	91.392
2008	92.357
2009	91.892
2010	91.77
2011	91.791
2012	91.736
2013	91.502
2014	91.401
2015	90.984
2016	90.766
2017	90.728
2018	90.691
2019	90.656
2020	90.619
2021	90.584
2022	90.548