Year Percent 1993-01-01 50.2704 1994-01-01 48.6921 1995-01-01 49.5503 1996-01-01 51.5558 1997-01-01 51.9657 1998-01-01 51.1486 1999-01-01 52.0499 2000-01-01 53.5548 2001-01-01 55.5893 2002-01-01 53.9784 2003-01-01 53.0486 2004-01-01 51.4635 2005-01-01 47.9552 2006-01-01 46.8154 2007-01-01 44.6762 2008-01-01 47.2940 2009-01-01 51.3540 2010-01-01 46.6547 2011-01-01 45.3839 2012-01-01 45.6907 2013-01-01 47.6958 2014-01-01 48.4241 2015-01-01 49.9601 2016-01-01 52.2252