Year	Percent
1991	87.803
1992	87.11
1993	87.847
1994	87.882
1995	88.129
1996	88.027
1997	87.918
1998	88.587
1999	88.134
2000	86.826
2001	87.528
2002	89.89
2003	89.61
2004	88.426
2005	88.711
2006	87.732
2007	87.83
2008	88.281
2009	88.102
2010	87.181
2011	86.639
2012	86.391
2013	85.851
2014	86.101
2015	87.361
2016	87.764
2017	87.778
2018	87.77
2019	87.757
2020	87.737
2021	87.717
2022	87.698