Year Percent 1998-01-01 39.33720000000000 1999-01-01 42.46860000000000 2000-01-01 45.80000000000000 2001-01-01 45.80000000000000 2002-01-01 42.50700000000000 2003-01-01 45.83660000000000 2004-01-01 44.51130000000000 2005-01-01 46.82520000000000 2006-01-01 46.54600000000001 2007-01-01 51.58810000000000 2008-01-01 48.66270000000000 2009-01-01 51.64080000000000 2010-01-01 59.40980000000000 2011-01-01 55.70690000000000 2012-01-01 56.27410000000000 2013-01-01 56.62900000000000 2014-01-01 54.75610000000000 2015-01-01 51.29970000000000 2016-01-01 52.48870000000000