Year Percent 1998-01-01 43.2819 1999-01-01 41.0295 2000-01-01 41.7000 2001-01-01 43.3000 2002-01-01 40.9989 2003-01-01 40.5525 2004-01-01 32.0981 2005-01-01 28.7435 2006-01-01 30.6757 2007-01-01 31.7847 2008-01-01 36.1160 2009-01-01 36.2202 2010-01-01 35.8226 2011-01-01 38.3388 2012-01-01 36.4544 2013-01-01 36.2576 2014-01-01 42.8686