Year	Percent
1991	92.125
1992	91.362
1993	90.353
1994	89.693
1995	88.332
1996	87.838
1997	87.798
1998	88.099
1999	88.382
2000	88.38
2001	88.091
2002	87.546
2003	86.776
2004	86.05
2005	85.597
2006	85.336
2007	85.343
2008	85.455
2009	85.54
2010	85.457
2011	85.306
2012	85.045
2013	85.622
2014	86.074
2015	85.794
2016	85.405
2017	85.239
2018	85.071
2019	84.896
2020	84.712
2021	84.527
2022	84.34