Year	Percent
1991	84.125
1992	84.098
1993	84.045
1994	84.005
1995	83.989
1996	84.048
1997	84.107
1998	84.16
1999	84.202
2000	84.223
2001	84.649
2002	85.116
2003	85.422
2004	86.297
2005	87.194
2006	87.371
2007	87.516
2008	87.624
2009	87.667
2010	87.684
2011	88.694
2012	89.66
2013	89.279
2014	88.843
2015	88.073
2016	87.795
2017	87.874
2018	87.96
2019	88.05
2020	88.096
2021	88.139
2022	88.186