Year Percent 1998-01-01 2.6106599999999998 1999-01-01 4.3292600000000000 2000-01-01 2.4229300000000000 2001-01-01 2.6369400000000000 2002-01-01 2.5833200000000000 2003-01-01 2.2208500000000000 2004-01-01 2.5298800000000000 2005-01-01 2.4103700000000000 2006-01-01 2.6912599999999998 2007-01-01 2.9739100000000000 2008-01-01 2.5377099999999997 2009-01-01 2.8099300000000000 2010-01-01 2.5985000000000000 2011-01-01 2.4110600000000000 2012-01-01 2.2935000000000000 2013-01-01 2.1700700000000000 2014-01-01 2.0367400000000000 2015-01-01 1.7873000000000000 2016-01-01 1.9516700000000000