Year Percent 1996-01-01 3.3256300000000003 1997-01-01 3.3563000000000000 1998-01-01 3.0384900000000004 1999-01-01 2.8968300000000000 2000-01-01 2.9265400000000000 2001-01-01 2.8022299999999998 2002-01-01 2.7877700000000000 2003-01-01 2.7824600000000000 2004-01-01 2.8063100000000000 2005-01-01 2.9795400000000000 2006-01-01 2.6627500000000000 2007-01-01 2.3882900000000000 2008-01-01 2.7265200000000003 2009-01-01 2.6747400000000003 2010-01-01 3.0420400000000000 2011-01-01 3.2521600000000000 2012-01-01 3.2442599999999997 2013-01-01 3.3496000000000000 2014-01-01 3.3312699999999995 2015-01-01 3.3776500000000000 2016-01-01 2.8653700000000000