Year Percent 1996-01-01 30.582500000000000 1997-01-01 34.678700000000000 1998-01-01 30.701500000000000 1999-01-01 33.287900000000000 2000-01-01 47.383400000000000 2001-01-01 43.215500000000000 2002-01-01 32.666100000000000 2003-01-01 62.071999999999996 2004-01-01 56.497200000000000 2005-01-01 55.282600000000000 2006-01-01 55.278700000000000 2007-01-01 52.042700000000000 2008-01-01 55.849600000000000 2009-01-01 51.532400000000000 2010-01-01 49.126000000000005 2011-01-01 51.984400000000000 2012-01-01 50.677300000000000 2013-01-01 48.482200000000000 2014-01-01 48.652400000000000 2015-01-01 50.576800000000000 2016-01-01 40.911800000000000