Year Percent 1996-01-01 46.0332 1997-01-01 39.1386 1998-01-01 36.2234 1999-01-01 32.8474 2000-01-01 34.3173 2001-01-01 56.4792 2002-01-01 22.0859 2003-01-01 40.8907 2004-01-01 36.1966 2005-01-01 44.8735 2006-01-01 48.8777 2007-01-01 43.0334 2008-01-01 36.9769 2009-01-01 48.7802 2010-01-01 48.3749 2011-01-01 44.5281 2012-01-01 48.8084 2013-01-01 45.0952 2014-01-01 44.4678