Year Percent 1995-01-01 7.09747987288784 1996-01-01 6.90334088219982 1997-01-01 6.15791388644771 1998-01-01 5.53639056733455 1999-01-01 5.58606662566173 2000-01-01 4.62595622450375 2001-01-01 4.60608801110414 2002-01-01 4.58668869270002 2003-01-01 5.40628851198047 2004-01-01 5.50764425288105 2005-01-01 4.83078241521485 2006-01-01 3.89858243399535 2007-01-01 3.79897043164988 2008-01-01 3.43346986579617 2009-01-01 6.00911160238794 2010-01-01 7.46303444545787 2011-01-01 7.57279199233309 2012-01-01 7.52407173517170 2013-01-01 6.99536833830095 2014-01-01 6.59281033776353 2015-01-01 6.16961789419842 2016-01-01 6.18084327327485 2017-01-01 5.74329276936686