Year	Percent
1991	85.841
1992	86.114
1993	86.771
1994	86.857
1995	86.669
1996	86.842
1997	86.583
1998	86.528
1999	86.606
2000	86.956
2001	87.371
2002	87.18
2003	87.385
2004	87.438
2005	87.879
2006	88.185
2007	88.538
2008	89.131
2009	89.788
2010	90.156
2011	89.848
2012	89.919
2013	90.155
2014	90.387
2015	90.393
2016	90.183
2017	90.046
2018	90.21
2019	90.366
2020	90.43
2021	90.519
2022	90.59