Year	Percent
1979	84.80034
1980	86.10988
1981	86.07681
1982	85.56171
1983	85.18497
1984	85.00452
1985	84.73899
1986	84.72831
1987	84.53833
1988	85.55041
1989	85.76658
1991	86.70967
1992	86.54801
1993	86.48487
1994	86.3843
1995	87.90399
1996	85.37662
1997	86.05011
1998	85.44325
1999	84.38019
2001	84.58939
2002	84.818
2003	84.99623
2004	84.36728
2005	93.61767
2006	84.90566
2007	84.62178
2008	84.92441
2011	85.00175
2012	84.67608
2013	85.08827
2014	85.37675
2015	86.0136