Year Percent 1997-01-01 0.7352760000000000 1998-01-01 1.6233100000000000 1999-01-01 1.6233100000000000 2000-01-01 1.6233100000000000 2001-01-01 1.1816100000000000 2002-01-01 1.2501900000000000 2003-01-01 1.1535000000000000 2004-01-01 1.0871899999999999 2005-01-01 1.0301000000000000 2006-01-01 0.8482190000000001 2007-01-01 0.9345240000000000 2008-01-01 1.0710300000000000 2009-01-01 1.0680800000000000 2010-01-01 1.0315299999999998 2011-01-01 0.9667070000000000 2012-01-01 1.9091099999999999 2013-01-01 3.8250800000000003 2014-01-01 4.6544800000000000 2015-01-01 4.1811900000000000 2016-01-01 3.7194599999999998