Year Percent 1998-01-01 34.193800000000000 1999-01-01 34.609600000000000 2000-01-01 38.200000000000000 2001-01-01 40.200000000000000 2002-01-01 39.852000000000000 2003-01-01 40.548400000000000 2004-01-01 43.968999999999994 2005-01-01 40.060000000000000 2006-01-01 42.433700000000000 2007-01-01 50.114500000000000 2008-01-01 42.963800000000000 2009-01-01 44.788200000000000 2010-01-01 44.788200000000000 2011-01-01 44.788200000000000 2012-01-01 52.549500000000000 2013-01-01 55.086100000000000 2014-01-01 56.930100000000000 2015-01-01 56.603600000000000 2016-01-01 54.121600000000000