Year Percent 1995-01-01 8.50785454260428 1996-01-01 7.96457371224467 1997-01-01 7.59034353180617 1998-01-01 6.96930009723538 1999-01-01 6.38858950996367 2000-01-01 5.45740053964180 2001-01-01 5.96178958890114 2002-01-01 6.60920433082838 2003-01-01 6.84754854687766 2004-01-01 6.11745194753485 2005-01-01 5.40649621036546 2006-01-01 5.34090988137443 2007-01-01 5.22613859006390 2008-01-01 5.76459811214722 2009-01-01 8.08854111481468 2010-01-01 7.44109315400743 2011-01-01 7.19133050841084 2012-01-01 6.62103071741742 2013-01-01 6.83972785254388 2014-01-01 6.75751172502516 2015-01-01 6.63444466881560 2016-01-01 6.99170769459896 2017-01-01 6.26675885734422