Year Percent 1998-01-01 4.50 1999-01-01 2.94 2000-01-01 2.88 2001-01-01 3.06 2002-01-01 3.19 2003-01-01 3.30 2004-01-01 2.92 2005-01-01 2.79 2006-01-01 2.75 2007-01-01 2.87 2008-01-01 3.04 2009-01-01 3.16 2010-01-01 3.05 2011-01-01 2.86 2012-01-01 3.04 2013-01-01 3.09 2014-01-01 3.01 2015-01-01 2.93 2016-01-01 3.00