Year Percent 1996-01-01 25.34 1997-01-01 45.09 1998-01-01 39.41 1999-01-01 19.00 2000-01-01 15.75 2001-01-01 19.00 2002-01-01 25.00 2003-01-01 16.50 2004-01-01 17.75 2005-01-01 18.00 2006-01-01 13.25 2007-01-01 11.25 2008-01-01 13.75 2009-01-01 8.75 2010-01-01 10.75 2011-01-01 11.00 2012-01-01 7.25 2013-01-01 10.00 2014-01-01 11.75 2015-01-01 14.25 2016-01-01 13.75 2017-01-01 7.00