Year Percent 1996-01-01 91.7583 1997-01-01 15.2750 1998-01-01 24.7417 1999-01-01 26.0333 2000-01-01 17.9250 2001-01-01 11.3000 2002-01-01 10.7000 2003-01-01 8.0000 2004-01-01 6.2000 2005-01-01 7.5000 2006-01-01 6.5000 2007-01-01 5.6000 2008-01-01 8.5000 2009-01-01 5.5000 2010-01-01 4.2000 2011-01-01 3.6000 2012-01-01 3.3000 2013-01-01 4.3000 2014-01-01 6.0000 2015-01-01 5.3700 2016-01-01 5.3300