Year	Percent
1970-01-01	98.48640000000000
1971-01-01	98.52900000000000
1972-01-01	98.71380000000000
1973-01-01	98.16620000000000
1974-01-01	97.27840000000000
1975-01-01	94.45540000000000
1976-01-01	93.46010000000000
1977-01-01	92.81820000000000
1978-01-01	93.60270000000000
1979-01-01	93.14190000000000
1980-01-01	92.18590000000000
1981-01-01	91.31430000000000
1982-01-01	91.17260000000000
1983-01-01	92.12570000000000
1984-01-01	86.81790000000000
1985-01-01	83.50600000000000
1986-01-01	86.55080000000000
1987-01-01	88.78470000000000
1988-01-01	89.69060000000000
1989-01-01	90.00660000000000
1990-01-01	90.06140000000000
1991-01-01	89.97760000000000
1992-01-01	90.59340000000000
1993-01-01	92.80750000000000
1994-01-01	94.61070000000000
1995-01-01	95.38260000000000
1996-01-01	96.10820000000000
1997-01-01	96.92210000000000
1998-01-01	97.52140000000000
1999-01-01	97.90490000000000
2000-01-01	98.39550000000000
2001-01-01	98.80920000000000
2002-01-01	99.22650000000000
2003-01-01	99.07430000000000
2004-01-01	99.24110000000000
2005-01-01	99.82830000000000
2006-01-01	99.84400000000000
2007-01-01	99.72030000000000
2008-01-01	99.56630000000000
2009-01-01	99.66400000000000
2010-01-01	99.78840000000000
2011-01-01	99.13000000000000
2012-01-01	98.43350000000000
2013-01-01	98.66210000000000
2014-01-01	98.76350000000000
2015-01-01	99.02540000000000
2016-01-01	99.74799999999999