Year	Percent
1975-01-01	95.23850000000000
1976-01-01	93.56650000000000
1977-01-01	91.70390000000000
1978-01-01	92.72730000000000
1979-01-01	94.17060000000000
1980-01-01	94.79160000000000
1981-01-01	95.17160000000000
1982-01-01	95.07030000000000
1983-01-01	94.83440000000000
1984-01-01	92.13440000000000
1985-01-01	90.41670000000000
1986-01-01	91.29770000000000
1987-01-01	91.49650000000000
1988-01-01	93.68290000000000
1989-01-01	95.37070000000000
1990-01-01	95.49830000000000
1991-01-01	95.43810000000000
1992-01-01	95.96400000000000
1993-01-01	96.66580000000000
1994-01-01	96.81770000000000
1995-01-01	97.31180000000000
1996-01-01	97.70060000000000
1997-01-01	97.91200000000000
1998-01-01	98.19360000000000
1999-01-01	97.80030000000000
2000-01-01	97.93060000000000
2001-01-01	98.54210000000000
2002-01-01	98.58110000000000
2003-01-01	97.85790000000000
2004-01-01	97.93940000000000
2005-01-01	98.89000000000000
2006-01-01	99.15799999999999
2007-01-01	99.44100000000000
2008-01-01	99.53950000000000
2009-01-01	99.54930000000000
2010-01-01	99.64420000000000
2011-01-01	99.38260000000000
2012-01-01	99.06610000000000
2013-01-01	98.88390000000000
2014-01-01	98.46150000000000
2015-01-01	98.14299999999999
2016-01-01	97.89000000000000