Year Percent 1990-01-01 7.92 1991-01-01 7.20 1992-01-01 7.20 1993-01-01 10.08 1994-01-01 10.08 1995-01-01 10.44 1996-01-01 9.00 1997-01-01 8.55 1998-01-01 4.59 1999-01-01 3.24 2000-01-01 3.24 2001-01-01 3.24 2002-01-01 2.70 2003-01-01 2.70 2004-01-01 3.33 2005-01-01 3.33 2006-01-01 3.33 2007-01-01 3.33 2008-01-01 2.79 2009-01-01 2.79 2010-01-01 3.25 2011-01-01 3.25 2012-01-01 3.25 2013-01-01 3.25 2014-01-01 3.25 2015-01-01 2.90 2016-01-01 2.90 2017-01-01 2.90