Year	Percent
1991	91.402
1992	90.694
1993	91.078
1994	90.811
1995	90.635
1996	90.286
1997	90.457
1998	90.56
1999	90.073
2000	89.878
2001	90.108
2002	89.737
2003	89.515
2004	88.846
2005	87.418
2006	87.149
2007	87.252
2008	87.042
2009	87.134
2010	87.002
2011	86.392
2012	86.523
2013	86.138
2014	85.961
2015	85.968
2016	86.141
2017	86.155
2018	86.126
2019	86.085
2020	86.049
2021	86.021
2022	85.993