Year	%
1974	62.24481
1976	69.58413
1977	67.31457
1978	68.21501
1979	66.8912
1980	69.80812
1982	68.78663
1984	48.26363
1985	67.03692
1986	71.51491
1987	73.56244
1988	73.47606
1989	82.56733
1990	66.48562
1991	99.30979
1992	91.9113
1993	92.35491
1994	90.80654
1996	87.04502
1998	84.21754
1999	87.58292
2000	88.48069
2001	89.4495
2002	88.36009
2003	88.3336
2005	87.59866
2006	88.89124
2007	87.94217
2008	89.97871
2009	91.62894
2010	91.94356
2011	92.31315
2012	93.70424
2013	92.19314
2014	90.72267
2015	91.13783
2016	92.48175
2017	92.65343