Year Percent 2001-01-01 8.4111300000000000 2002-01-01 7.6498100000000000 2003-01-01 4.7212900000000000 2004-01-01 5.4989700000000000 2005-01-01 5.4053300000000000 2006-01-01 5.8368600000000000 2007-01-01 9.2195400000000000 2008-01-01 7.3714100000000010 2009-01-01 5.5067200000000000 2010-01-01 2.2895300000000000 2011-01-01 2.5340000000000003 2012-01-01 3.2608700000000000 2013-01-01 2.8987000000000000 2014-01-01 2.6731500000000000 2015-01-01 3.1972500000000000 2016-01-01 3.3032800000000004 2017-01-01 3.1584200000000000