Year Percent 1998-01-01 1.5341100000000000 1999-01-01 1.3445600000000000 2000-01-01 1.7242000000000000 2001-01-01 1.7709000000000000 2002-01-01 1.6962800000000000 2003-01-01 1.7087299999999999 2004-01-01 2.2941800000000000 2005-01-01 1.8647900000000002 2006-01-01 2.0227700000000000 2007-01-01 2.0144300000000000 2008-01-01 2.3941300000000000 2009-01-01 2.5334500000000000 2010-01-01 1.7952200000000000 2011-01-01 1.8776800000000000 2012-01-01 1.6405700000000000 2013-01-01 1.4389399999999999 2014-01-01 1.4838900000000000 2015-01-01 1.5880100000000001 2016-01-01 1.4636400000000000