Year Percent 2003-01-01 4.76787954830615 2004-01-01 7.08283313325330 2005-01-01 5.81395348837209 2006-01-01 6.22914349276974 2007-01-01 4.71216511140951 2008-01-01 6.03036107120255 2009-01-01 6.10185089107557 2010-01-01 5.09644672113741 2011-01-01 6.24537449048885 2012-01-01 5.88744033781276 2013-01-01 6.38616639991271 2014-01-01 5.76032969361449 2015-01-01 7.32721959321929 2016-01-01 6.62828287136004 2017-01-01 5.50360986056823