Year Percent 1998-01-01 62.5482 1999-01-01 55.6613 2000-01-01 53.8000 2001-01-01 51.4000 2002-01-01 49.3661 2003-01-01 48.3540 2004-01-01 51.0454 2005-01-01 47.5702 2006-01-01 47.7665 2007-01-01 44.3948 2008-01-01 47.5433 2009-01-01 45.2384 2010-01-01 44.6174 2011-01-01 46.8680 2012-01-01 47.9376 2013-01-01 48.6768 2014-01-01 49.3490 2015-01-01 48.5482 2016-01-01 56.3780