Year Percent 1999-01-01 55.7447446291473 2000-01-01 55.4806541940134 2001-01-01 55.6320859855509 2002-01-01 55.1354317943134 2003-01-01 54.9796121249189 2004-01-01 55.0102759408343 2005-01-01 55.0248515336600 2006-01-01 55.7867727779422 2007-01-01 55.4327185011534 2008-01-01 55.8478102585408 2009-01-01 53.1942257136350 2010-01-01 51.5070146036413 2011-01-01 51.5170387841636 2012-01-01 51.0094125083247 2013-01-01 50.6907150187937 2014-01-01 51.2026478221447