Year Percent 1999-01-01 3.675 2000-01-01 3.325 2001-01-01 3.475 2002-01-01 4.050 2003-01-01 4.375 2004-01-01 5.175 2005-01-01 5.475 2006-01-01 5.025 2007-01-01 4.550 2008-01-01 3.950 2009-01-01 5.575 2010-01-01 5.075 2011-01-01 4.625 2012-01-01 5.025 2013-01-01 5.450 2014-01-01 5.950 2015-01-01 6.225 2016-01-01 6.525 2017-01-01 6.000