Year Percent 1996-01-01 28.982400000000000 1997-01-01 33.698400000000000 1998-01-01 34.031100000000000 1999-01-01 29.353400000000000 2000-01-01 30.679100000000000 2001-01-01 35.091800000000000 2002-01-01 33.331200000000000 2003-01-01 32.425000000000000 2004-01-01 23.471999999999998 2005-01-01 23.127700000000000 2006-01-01 66.175000000000000 2007-01-01 76.228200000000000 2008-01-01 83.288100000000000 2009-01-01 45.188100000000000 2010-01-01 40.211200000000000 2011-01-01 46.158600000000000 2012-01-01 44.539300000000000 2013-01-01 45.175100000000000 2014-01-01 39.390900000000000 2015-01-01 39.306000000000000 2016-01-01 37.230700000000000