Year	%
1978	76.32022
1979	76.39949
1980	77.55075
1981	76.37622
1982	75.02999
1983	75.01431
1984	77.61798
1985	78.31353
1986	78.2517
1987	77.82291
1988	77.41757
1989	77.19613
1990	77.16355
1991	77.58412
1992	77.25274
1993	77.31292
1994	77.99877
1995	78.08463
1996	82.0471
1997	79.26952
1998	79.48774
1999	80.61508
2000	81.94421
2001	82.18619
2002	83.83863
2009	91.3804
2010	90.88886
2011	90.99847
2012	91.65439
2013	92.29762
2014	92.97778
2015	93.36587
2016	93.17744