Year Percent 1991-01-01 9.46011168683127 1992-01-01 8.61075493756340 1993-01-01 8.63637065176996 1994-01-01 8.65423191354735 1995-01-01 9.07103169364101 1996-01-01 9.20814281321744 1997-01-01 9.62124256678564 1998-01-01 10.50637670823150 1999-01-01 10.74483204122200 2000-01-01 10.36320896285310 2001-01-01 10.43504561144000 2002-01-01 10.37160526189010 2003-01-01 10.16130614747410 2004-01-01 10.26123256518310 2005-01-01 10.32496052305880 2006-01-01 10.29119639336760 2007-01-01 9.69183603053320 2008-01-01 10.35134296023230 2009-01-01 10.37318389432920 2010-01-01 9.99046077835419 2011-01-01 10.12498090076820 2012-01-01 9.98254050691659 2013-01-01 10.07688925143730 2014-01-01 10.18029859832450 2015-01-01 10.43960172924660 2016-01-01 10.23481990205140 2017-01-01 10.17466877856770