Year Percent 1999-01-01 1.91 2000-01-01 1.96 2001-01-01 2.14 2002-01-01 2.50 2003-01-01 2.47 2004-01-01 2.43 2005-01-01 2.55 2006-01-01 2.53 2007-01-01 2.32 2008-01-01 2.22 2009-01-01 2.20 2010-01-01 2.20 2011-01-01 2.20 2012-01-01 2.20 2013-01-01 1.91 2014-01-01 1.85 2015-01-01 1.79 2016-01-01 1.78