Year	Percent
1974	95.75472
1975	96.43411
1976	95.3
1977	102.62766
1978	98.32558
1979	93.02736
1982	93.13373
1983	100.78681
1984	98.71988
1985	96.91497
1986	97.99525
1992	72.60414
1993	74.04161
1994	72.76364
1995	71.75773
1996	71.36527
1997	70.30566
1998	72.14254
1999	70.88165
2000	69.81436
2001	68.89455
2002	68.10324
2003	67.47657
2004	68.20087
2005	68.35248
2006	69.58835
2007	72.31504
2009	72.53324
2010	72.36156
2011	72.91806
2012	74.24091
2013	74.37731
2014	72.96979
2015	70.93619
2016	70.05296
2017	69.48703