Year Percent 2000-01-01 3.6703300000000003 2001-01-01 3.7200000000000000 2002-01-01 3.6800000000000000 2003-01-01 4.0300000000000000 2004-01-01 4.2800000000000000 2005-01-01 4.6100000000000000 2006-01-01 4.7600000000000000 2007-01-01 4.6300000000000000 2008-01-01 4.2700000000000000 2009-01-01 4.8800000000000000 2010-01-01 5.0400000000000000 2011-01-01 4.7600000000000000 2012-01-01 5.1100000000000000 2013-01-01 5.3700000000000000 2014-01-01 5.7100000000000000 2015-01-01 5.7000000000000000 2016-01-01 5.9000000000000000