Year Percent 1998-01-01 31.1316 1999-01-01 34.3837 2000-01-01 31.6001 2001-01-01 53.9062 2002-01-01 56.2080 2003-01-01 65.9817 2004-01-01 54.7945 2005-01-01 29.2412 2006-01-01 29.8825 2007-01-01 29.1036 2008-01-01 30.2273 2009-01-01 27.4902 2010-01-01 24.9124 2011-01-01 24.1955 2012-01-01 25.2569 2013-01-01 24.4233 2014-01-01 27.6071