Year Percent 1996-01-01 78.1748 1997-01-01 77.3849 1998-01-01 41.7628 1999-01-01 53.1868 2000-01-01 39.8773 2001-01-01 41.3163 2002-01-01 41.5916 2003-01-01 38.7553 2004-01-01 32.7805 2005-01-01 30.2995 2006-01-01 28.6780 2007-01-01 28.4117 2008-01-01 24.0688 2009-01-01 24.3409 2010-01-01 25.6868 2011-01-01 26.5812 2012-01-01 30.9234 2013-01-01 32.4600 2014-01-01 33.4714