Year	Percent
1971	0.77477
1976	0.84379
1977	0.86398
1978	0.88028
1979	0.89071
1980	0.89452
1981	0.89777
1982	0.90369
1983	0.90564
1984	0.90673
1985	0.91165
1986	0.92241
1987	0.93406
1988	0.94042
1989	0.94696
1990	0.95372
1991	0.95824
1992	0.9476
1999	0.95839
2000	0.94184
2001	0.96496
2002	0.97662
2003	0.9793
2004	0.99719
2005	1.00583
2006	1.02201
2007	1.00341
2008	1.00193
2009	1.00348
2010	1.01065
2011	1.02318
2012	1.02636
2013	1.03069
2014	1.03617
2015	1.02498
2016	1.01393