Year	Percent
1991	70.196
1992	72.808
1993	74.591
1994	75.857
1995	76.758
1996	77.974
1997	78.554
1998	78.766
1999	79.157
2000	79.609
2001	80.053
2002	80.42
2003	81.248
2004	81.288
2005	82.25
2006	82.381
2007	82.434
2008	83.67
2009	84.191
2010	84.536
2011	84.631
2012	84.742
2013	84.98
2014	84.821
2015	85.176
2016	85.299
2017	85.457
2018	85.716
2019	85.955
2020	86.121
2021	86.292
2022	86.45