Year Percent 1996-01-01 2.1553400000000003 1997-01-01 2.3448700000000002 1998-01-01 2.1410299999999998 1999-01-01 1.8341599999999998 2000-01-01 2.0597200000000000 2001-01-01 2.0512300000000000 2002-01-01 2.1344300000000000 2003-01-01 2.1992599999999998 2004-01-01 2.6223400000000003 2005-01-01 4.0209699999999990 2006-01-01 2.8269500000000000 2007-01-01 2.3235600000000000 2008-01-01 1.7264400000000002 2009-01-01 1.2621300000000000 2010-01-01 1.4429100000000001 2011-01-01 1.5915300000000000 2012-01-01 1.6872500000000000 2013-01-01 1.8420299999999998 2014-01-01 2.0224100000000000 2015-01-01 2.1185700000000000 2016-01-01 1.7211299999999998