Year Percent 1990-01-01 0.61153300000000000 1991-01-01 0.62876599999999990 1992-01-01 0.71241199999999990 1993-01-01 0.80388900000000010 1994-01-01 0.82681399999999990 1995-01-01 0.82112999999999990 1996-01-01 0.77365600000000000 1997-01-01 0.77968900000000010 1998-01-01 0.58905699999999990 1999-01-01 0.52521100000000000 2000-01-01 0.48428999999999994 2001-01-01 0.49133300000000000 2002-01-01 0.52601100000000000 2003-01-01 0.49685300000000000 2004-01-01 0.45896300000000000 2005-01-01 0.44343900000000000 2006-01-01 0.36307800000000000 2007-01-01 0.51732800000000000 2008-01-01 0.48123000000000000 2009-01-01 0.47579000000000000 2010-01-01 0.47631899999999994 2011-01-01 0.48738600000000000 2012-01-01 0.49431800000000004 2013-01-01 0.49271200000000000 2014-01-01 0.47492900000000000 2015-01-01 0.37815500000000000 2016-01-01 0.54699700000000010