Year	Percent
1991	79.3
1992	78.97
1993	77.809
1994	79.679
1995	80.292
1996	79.867
1997	81.238
1998	81.692
1999	82.811
2000	83.205
2001	82.483
2002	83.259
2003	83.362
2004	82.286
2005	82.773
2006	82.965
2007	83.483
2008	83.186
2009	82.159
2010	84.66
2011	84.482
2012	84.315
2013	84.717
2014	84.798
2015	84.315
2016	84.018
2017	84.062
2018	84.375
2019	84.633
2020	84.826
2021	85.026
2022	85.176