Year	Percent
1975-01-01	91.50950000000000
1976-01-01	92.02190000000000
1977-01-01	92.36090000000000
1978-01-01	92.52730000000000
1979-01-01	92.73210000000000
1980-01-01	92.48650000000000
1981-01-01	92.85820000000000
1982-01-01	93.38110000000000
1983-01-01	93.19690000000000
1984-01-01	90.18170000000000
1985-01-01	86.54720000000000
1986-01-01	84.82240000000000
1987-01-01	83.52799999999999
1988-01-01	86.28000000000000
1989-01-01	90.06230000000000
1990-01-01	91.25870000000000
1991-01-01	91.99910000000000
1992-01-01	93.64410000000000
1993-01-01	95.40730000000000
1994-01-01	95.67350000000000
1995-01-01	96.12220000000000
1996-01-01	97.03750000000000
1997-01-01	97.42140000000000
1998-01-01	97.70070000000000
1999-01-01	97.93180000000000
2000-01-01	98.02950000000000
2001-01-01	98.13370000000000
2002-01-01	98.26350000000000
2003-01-01	98.32780000000000
2004-01-01	98.48620000000000
2005-01-01	98.70740000000000
2006-01-01	99.06600000000000
2007-01-01	99.37160000000000
2008-01-01	99.41230000000000
2009-01-01	99.60960000000000
2010-01-01	99.78500000000000
2011-01-01	99.79880000000000
2012-01-01	99.90420000000000
2013-01-01	100.00000000000000
2014-01-01	99.89810000000000
2015-01-01	99.89640000000000