Year	Percent
1963-01-01	98.93760000000000
1964-01-01	99.14310000000000
1965-01-01	99.14310000000000
1966-01-01	98.84220000000000
1967-01-01	97.32540000000000
1968-01-01	98.17880000000000
1969-01-01	99.74590000000000
1970-01-01	99.74590000000000
1971-01-01	99.24270000000000
1972-01-01	97.43370000000000
1973-01-01	98.27690000000000
1974-01-01	99.98100000000001
1975-01-01	99.98100000000001
1976-01-01	98.70440000000000
1977-01-01	98.93410000000000
1978-01-01	99.56790000000000
1979-01-01	97.35450000000000
1980-01-01	93.05170000000000
1981-01-01	87.77799999999999
1982-01-01	82.92500000000000
1983-01-01	79.23420000000000
1984-01-01	77.24410000000000
1985-01-01	76.91370000000000
1986-01-01	77.38580000000000
1987-01-01	79.32800000000000
1988-01-01	81.41310000000000
1989-01-01	82.20550000000000
1990-01-01	82.34160000000000
1991-01-01	82.12480000000000
1992-01-01	82.55780000000000
1993-01-01	81.53220000000000
1994-01-01	76.61220000000000
1995-01-01	75.36200000000000
1996-01-01	77.29280000000000
1997-01-01	77.08270000000000
1998-01-01	75.60500000000000
1999-01-01	72.41520000000000
2000-01-01	72.05840000000000
2001-01-01	74.65340000000000
2002-01-01	75.99720000000000
2003-01-01	76.22690000000000
2004-01-01	78.67600000000000
2005-01-01	81.61830000000000
2006-01-01	84.58860000000000
2007-01-01	87.44420000000000
2008-01-01	88.41030000000000
2009-01-01	84.66120000000000
2010-01-01	82.58810000000000
2011-01-01	82.11500000000000
2012-01-01	80.76380000000000
2013-01-01	81.82030000000000
2014-01-01	83.82110000000000
2015-01-01	85.76190000000000
2016-01-01	86.37310000000000