Year Percent 1995-01-01 6.09 1996-01-01 6.21 1997-01-01 6.54 1998-01-01 6.84 1999-01-01 6.84 2000-01-01 6.51 2001-01-01 5.22 2002-01-01 5.42 2003-01-01 6.24 2004-01-01 6.85 2005-01-01 6.96 2006-01-01 7.01 2007-01-01 7.20 2008-01-01 6.21 2009-01-01 7.75 2010-01-01 7.98 2011-01-01 7.56 2012-01-01 7.77 2013-01-01 8.47 2014-01-01 9.25 2015-01-01 10.07 2016-01-01 10.66