Year Percent 1998-01-01 43.056000000000004 1999-01-01 42.005400000000000 2000-01-01 44.300000000000000 2001-01-01 40.800000000000000 2002-01-01 33.786400000000000 2003-01-01 27.212000000000000 2004-01-01 45.382900000000000 2005-01-01 37.759800000000000 2006-01-01 38.473100000000000 2007-01-01 38.695400000000000 2008-01-01 38.823000000000000 2009-01-01 34.206300000000000 2010-01-01 35.703300000000000 2011-01-01 38.396200000000000 2012-01-01 41.065700000000000 2013-01-01 29.009500000000000 2014-01-01 42.661100000000000 2015-01-01 42.000500000000000 2016-01-01 44.076200000000000