Year Percent 1996-01-01 35.430300000000000 1997-01-01 35.209700000000000 1998-01-01 26.734500000000000 1999-01-01 23.415900000000000 2000-01-01 16.076500000000000 2001-01-01 16.866700000000000 2002-01-01 18.538200000000000 2003-01-01 16.082600000000000 2004-01-01 7.827470000000000 2005-01-01 21.126100000000000 2006-01-01 11.259800000000000 2007-01-01 13.849800000000000 2008-01-01 -8.843810000000001 2009-01-01 -7.164430000000000 2010-01-01 7.983600000000000 2011-01-01 9.436739999999999 2012-01-01 14.471400000000000 2013-01-01 17.744800000000000 2014-01-01 15.114000000000000 2015-01-01 16.044900000000000 2016-01-01 18.644100000000000