Year	Percent
1975-01-01	74.90570000000000
1976-01-01	76.81970000000000
1977-01-01	85.92410000000000
1978-01-01	92.96540000000000
1979-01-01	83.31910000000000
1980-01-01	77.37200000000000
1981-01-01	82.89330000000000
1982-01-01	82.24300000000000
1983-01-01	80.62730000000000
1984-01-01	81.84630000000000
1985-01-01	84.91190000000000
1986-01-01	87.61620000000000
1987-01-01	87.64120000000000
1988-01-01	86.94520000000000
1989-01-01	86.57540000000000
1990-01-01	88.01820000000000
1991-01-01	85.75830000000000
1992-01-01	83.27070000000000
1993-01-01	81.44860000000000
1994-01-01	75.38740000000000
1995-01-01	70.07730000000000
1996-01-01	76.28960000000000
1997-01-01	94.01799999999999
1998-01-01	90.93970000000000
1999-01-01	81.37030000000000
2000-01-01	76.97700000000000
2001-01-01	77.07720000000000
2002-01-01	77.29070000000000
2003-01-01	73.55320000000000
2004-01-01	67.77450000000000
2005-01-01	66.76100000000001
2006-01-01	70.11510000000000
2007-01-01	73.24070000000000
2008-01-01	75.48810000000000
2009-01-01	81.29810000000000
2010-01-01	85.56100000000000
2011-01-01	82.72500000000000
2012-01-01	77.86100000000000
2013-01-01	73.72680000000000
2014-01-01	69.85140000000000
2015-01-01	62.73270000000000
2016-01-01	58.46450000000000