Year Percent 1997-01-01 5.9989099999999995 1998-01-01 6.4215400000000000 1999-01-01 6.0393900000000000 2000-01-01 5.9104100000000000 2001-01-01 6.1032000000000000 2002-01-01 5.5327400000000000 2003-01-01 4.2529000000000000 2004-01-01 3.6053400000000000 2005-01-01 5.8910599999999995 2006-01-01 5.4849700000000000 2007-01-01 4.4846500000000000 2008-01-01 3.5557800000000004 2009-01-01 6.2098400000000000 2010-01-01 5.4262300000000000 2011-01-01 4.3938100000000000 2012-01-01 4.3335400000000000 2013-01-01 1.9099300000000000 2014-01-01 6.9522900000000000 2015-01-01 8.3484000000000000 2016-01-01 11.9903000000000000