Year	%
1970	86.05042
1971	82.07407
1973	82.41895
1976	95.46569
1977	98.79195
1979	97.2155
1980	97.80488
1981	99.08616
1982	99.24623
1983	100
1984	97.73116
1985	98.9432
1986	95.30917
1987	99.0232
1988	98.21674
1991	98.5932
1992	93.92733
1993	92.00143
1997	100
1998	100
1999	100
2000	98.25
2001	98.94242
2002	99.50218
2003	92.54808
2004	100
2007	100
2008	98.61111
2009	97.9564
2010	95.22546
2013	100
2014	98.37347
2015	94.72704
2016	97.96438
2017	97.48011