Year Percent 1996-01-01 1.7519900000000002 1997-01-01 1.7943799999999999 1998-01-01 1.8268799999999998 1999-01-01 1.9270100000000000 2000-01-01 2.0957200000000000 2001-01-01 2.0529400000000000 2002-01-01 2.0322900000000000 2003-01-01 2.1714400000000000 2004-01-01 2.2025600000000000 2005-01-01 2.1742600000000000 2006-01-01 2.0711600000000000 2007-01-01 1.5381700000000000 2008-01-01 1.6849700000000000 2009-01-01 1.9632599999999998 2010-01-01 2.0935300000000000 2011-01-01 1.9778099999999998 2012-01-01 1.9045100000000000 2013-01-01 1.8606700000000000 2014-01-01 1.7283099999999998 2015-01-01 1.5910000000000000 2016-01-01 1.3720299999999999