Year	Percent
1975-01-01	97.42010000000000
1976-01-01	96.06890000000000
1977-01-01	94.97450000000000
1978-01-01	94.80170000000000
1979-01-01	94.98010000000000
1980-01-01	94.46840000000000
1981-01-01	94.25990000000000
1982-01-01	94.36170000000000
1983-01-01	94.65000000000000
1984-01-01	91.09850000000000
1985-01-01	88.19140000000000
1986-01-01	89.21000000000000
1987-01-01	91.17810000000000
1988-01-01	92.49799999999999
1989-01-01	93.18260000000000
1990-01-01	93.27700000000000
1991-01-01	93.15020000000000
1992-01-01	94.33760000000000
1993-01-01	95.09830000000000
1994-01-01	95.02590000000000
1995-01-01	95.83380000000000
1996-01-01	96.91750000000000
1997-01-01	97.76410000000000
1998-01-01	97.93980000000000
1999-01-01	98.25120000000000
2000-01-01	98.11890000000000
2001-01-01	97.94060000000000
2002-01-01	98.30700000000000
2003-01-01	98.59000000000000
2004-01-01	98.71040000000000
2005-01-01	98.88290000000000
2006-01-01	99.05270000000000
2007-01-01	99.48330000000000
2008-01-01	99.57380000000000
2009-01-01	98.16360000000000
2010-01-01	96.65190000000000
2011-01-01	96.23590000000000
2012-01-01	96.23190000000000
2013-01-01	96.54700000000001
2014-01-01	96.68680000000000
2015-01-01	96.56360000000000
2016-01-01	96.83690000000000