Year	Percent
1981-01-01	99.69730000000000
1982-01-01	99.50620000000000
1983-01-01	99.13150000000000
1984-01-01	99.03060000000000
1985-01-01	99.39410000000000
1986-01-01	99.84840000000000
1987-01-01	99.56750000000000
1988-01-01	98.39250000000000
1989-01-01	97.37130000000000
1990-01-01	97.66170000000000
1991-01-01	98.33850000000000
1992-01-01	98.79350000000000
1993-01-01	99.13590000000000
1994-01-01	96.16750000000000
1995-01-01	92.45070000000000
1996-01-01	91.66580000000000
1997-01-01	89.91480000000000
1998-01-01	88.46030000000000
1999-01-01	88.57130000000000
2000-01-01	88.31690000000000
2001-01-01	88.29040000000000
2002-01-01	88.29410000000000
2003-01-01	88.71010000000000
2004-01-01	89.78530000000000
2005-01-01	91.58270000000000
2006-01-01	92.92190000000000
2007-01-01	93.27850000000000
2008-01-01	95.74440000000000
2009-01-01	97.83650000000000
2010-01-01	97.17060000000000
2011-01-01	96.34600000000000
2012-01-01	96.49210000000000
2013-01-01	96.43700000000001
2014-01-01	95.84510000000000
2015-01-01	95.53299999999999
2016-01-01	94.52470000000000