Year Percent 2002-01-01 3.677740000000000 2003-01-01 2.646790000000000 2004-01-01 2.456260000000000 2005-01-01 2.682950000000000 2006-01-01 3.316350000000000 2007-01-01 3.678560000000000 2008-01-01 4.412420000000000 2009-01-01 4.519010000000000 2010-01-01 5.320380000000000 2011-01-01 5.825419999999999 2012-01-01 7.006700000000000 2013-01-01 7.412280000000000 2014-01-01 7.645600000000000 2015-01-01 6.602680000000000 2016-01-01 5.805060000000000 2017-01-01 5.970760000000000