Year Percent 1998-01-01 27.7512 1999-01-01 41.3923 2000-01-01 52.7000 2001-01-01 20.9000 2002-01-01 11.1911 2003-01-01 41.9410 2004-01-01 46.8411 2005-01-01 40.0352 2006-01-01 38.9023 2007-01-01 47.2355 2008-01-01 52.1023 2009-01-01 43.2888 2010-01-01 31.4303 2011-01-01 35.7687 2012-01-01 42.6018 2013-01-01 14.2586 2014-01-01 38.3648 2015-01-01 43.2771