Year Percent 1996-01-01 59.0909 1997-01-01 58.2152 1998-01-01 53.5904 1999-01-01 54.5566 2000-01-01 51.3469 2001-01-01 53.8269 2002-01-01 47.0257 2003-01-01 50.0000 2004-01-01 54.5436 2005-01-01 54.3683 2006-01-01 46.2990 2007-01-01 41.5596 2008-01-01 43.7500 2009-01-01 43.7500 2010-01-01 39.3531 2011-01-01 38.3645 2012-01-01 45.8333