Year	%
1974	64.38464
1976	73.55164
1977	73.66803
1978	75.05995
1979	73.11026
1980	73.72507
1982	75.10973
1984	55.95896
1985	75.53733
1986	79.31703
1987	79.8052
1988	77.43029
1989	86.24766
1990	69.32315
1991	95.72281
1992	92.0609
1993	92.20523
1994	91.94389
1996	88.26646
1998	85.08135
1999	87.49509
2000	87.0258
2001	87.49705
2002	86.34261
2003	85.2057
2005	82.3625
2006	83.90633
2007	82.43824
2008	83.71036
2009	85.13965
2010	84.51799
2011	84.50869
2012	86.77935
2013	84.96574
2014	83.89463
2015	86.16295
2016	87.85205
2017	88.27532