Year Percent 1996-01-01 3.3005100000000000 1997-01-01 3.1908900000000000 1998-01-01 3.0992900000000003 1999-01-01 2.9854400000000000 2000-01-01 2.9288500000000000 2001-01-01 3.1651900000000000 2002-01-01 3.5230400000000000 2003-01-01 3.7072300000000005 2004-01-01 3.6398000000000000 2005-01-01 3.5067900000000000 2006-01-01 3.4382000000000000 2007-01-01 3.3111500000000000 2008-01-01 3.2003700000000000 2009-01-01 3.2064600000000000 2010-01-01 3.0471100000000000 2011-01-01 3.0974000000000000 2012-01-01 3.1160799999999997 2013-01-01 3.1717400000000002 2014-01-01 3.1627500000000000 2015-01-01 3.1910000000000003 2016-01-01 3.2104200000000000