Year Percent 2000-01-01 23.89666030930510 2001-01-01 20.17209521634750 2002-01-01 14.74006524318240 2003-01-01 17.52552271070570 2004-01-01 23.62313217044370 2005-01-01 16.16880092911970 2006-01-01 9.93804072361684 2007-01-01 12.15083114726300 2008-01-01 12.47992817102400 2009-01-01 31.62500000000000 2010-01-01 35.37500000000000 2011-01-01 23.90000000000000 2012-01-01 22.92500000000000 2013-01-01 18.02500000000000 2014-01-01 19.22500000000000 2015-01-01 14.13811641706700 2016-01-01 15.90647376181060 2017-01-01 13.81732376929370