Year	Percent
1975-01-01	38.173700000000000
1976-01-01	36.740000000000000
1977-01-01	35.495400000000000
1978-01-01	32.241600000000000
1979-01-01	42.712400000000000
1980-01-01	40.909000000000000
1981-01-01	36.596400000000000
1982-01-01	36.411700000000000
1983-01-01	37.904000000000000
1984-01-01	38.586999999999996
1985-01-01	38.841300000000000
1986-01-01	37.361600000000000
1987-01-01	41.245700000000000
1988-01-01	42.986100000000000
1989-01-01	43.577300000000000
1990-01-01	44.561500000000000
1991-01-01	48.620100000000000
1992-01-01	53.244300000000000
1993-01-01	53.089000000000000
1994-01-01	49.918000000000000
1995-01-01	54.717900000000000
1996-01-01	57.998700000000000
1997-01-01	59.229800000000000
1998-01-01	57.394700000000000
1999-01-01	59.394300000000000
2000-01-01	60.758600000000000
2001-01-01	60.297700000000000
2002-01-01	65.832700000000000
2003-01-01	69.463900000000000
2004-01-01	70.196100000000000
2005-01-01	74.937700000000000
2006-01-01	76.067400000000000
2007-01-01	77.426300000000000
2008-01-01	78.537300000000000
2009-01-01	77.378000000000000
2010-01-01	82.430000000000000
2011-01-01	83.406100000000000
2012-01-01	91.798300000000000
2013-01-01	94.637500000000000
2014-01-01	95.102100000000000
2015-01-01	96.290300000000000
2016-01-01	92.584100000000000