Year	Percent
1980-01-01	0.51147500000000000
1981-01-01	0.40637000000000000
1982-01-01	0.47177100000000000
1983-01-01	0.49515400000000000
1984-01-01	0.46649100000000000
1985-01-01	0.46262200000000003
1986-01-01	0.42173299999999997
1987-01-01	0.40278000000000000
1988-01-01	0.39475500000000000
1989-01-01	0.37367000000000000
1990-01-01	0.35791300000000004
1991-01-01	0.37809000000000000
1992-01-01	0.38432300000000000
1993-01-01	0.39811799999999997
1994-01-01	0.41419100000000000
1995-01-01	0.42998100000000006
1996-01-01	0.42120400000000000
1997-01-01	0.42171200000000000
1998-01-01	0.41586400000000000
1999-01-01	0.42134600000000000
2000-01-01	0.36571000000000000
2001-01-01	0.42207700000000004
2002-01-01	0.40655399999999997
2003-01-01	0.43446599999999996
2004-01-01	0.43011200000000000
2005-01-01	0.42121899999999995
2006-01-01	0.41659100000000000
2007-01-01	0.37415500000000000
2008-01-01	0.39950800000000000
2009-01-01	0.43242700000000006
2010-01-01	0.42732000000000000
2011-01-01	0.37383099999999997
2012-01-01	0.36231500000000000
2013-01-01	0.35396500000000003
2014-01-01	0.33928800000000003
2015-01-01	0.37053100000000000
2016-01-01	0.37340600000000000
2017-01-01	0.36811200000000000