Year	%
1976	32.44374
1977	26.74663
1978	27.39787
1979	40.71456
1980	43.2561
1981	42.04257
1982	47.34318
1983	57.23848
1984	57.89899
1985	58.8417
1986	51.02192
1987	54.01991
1989	68.27543
1990	67.70635
1992	80.49589
1993	81.30174
1994	81.83097
1995	82.9033
1996	85.39894
1998	89.16556
1999	90.96724
2000	92.56728
2001	96.22457
2002	96.20005
2003	95.88318
2004	95.72473
2007	94.47909
2008	95.12363
2009	98.08535
2012	94.82559
2013	97.26449
2014	91.58123
2016	97.53871