Year Percent 1990-01-01 18.83 1991-01-01 18.47 1992-01-01 13.50 1993-01-01 8.82 1994-01-01 12.44 1995-01-01 13.99 1996-01-01 12.80 1997-01-01 20.00 1998-01-01 38.44 1999-01-01 12.51 2000-01-01 14.53 2001-01-01 17.62 2002-01-01 12.93 2003-01-01 8.31 2004-01-01 7.43 2005-01-01 12.75 2006-01-01 9.75 2007-01-01 8.00 2008-01-01 9.25 2009-01-01 6.50 2010-01-01 6.50 2011-01-01 6.00 2012-01-01 5.75 2013-01-01 7.50 2014-01-01 7.75 2015-01-01 7.50 2016-01-01 4.75 2017-01-01 4.25