Year Percent 1998-01-01 67.5 1999-01-01 65.4 2000-01-01 62.8 2001-01-01 63.9 2002-01-01 58.9 2003-01-01 45.4 2004-01-01 59.5 2005-01-01 63 2006-01-01 60 2007-01-01 50.7 2008-01-01 50.7 2009-01-01 50.7 2010-01-01 50.7