Year Percent 1996-01-01 2.8223900000000000 1997-01-01 1.8550099999999998 1998-01-01 2.7108700000000000 1999-01-01 5.3171100000000000 2000-01-01 3.2582200000000000 2001-01-01 2.8704099999999997 2002-01-01 3.9050800000000003 2003-01-01 4.8368000000000000 2004-01-01 3.8758199999999996 2005-01-01 2.2319800000000000 2006-01-01 5.7040600000000000 2007-01-01 5.4362200000000000 2008-01-01 3.9705699999999995 2009-01-01 6.1871900000000000 2010-01-01 4.4899900000000000 2011-01-01 2.9799500000000000 2012-01-01 4.8951600000000000 2013-01-01 2.0023500000000000 2014-01-01 2.2005500000000000 2015-01-01 3.1101900000000002 2016-01-01 3.4926500000000000