Year Percent 1995-01-01 19.3484 1996-01-01 30.2961 1997-01-01 38.5686 1998-01-01 43.7888 1999-01-01 35.8536 2000-01-01 24.3669 2001-01-01 22.3850 2002-01-01 21.3483 2003-01-01 21.7717 2004-01-01 23.2874 2005-01-01 24.0848 2006-01-01 24.1426 2007-01-01 21.3451 2008-01-01 18.6865 2009-01-01 17.4317 2010-01-01 15.6109 2011-01-01 15.0159 2012-01-01 15.7574 2013-01-01 15.6359 2014-01-01 14.7198