Year Percent 1999-01-01 7.76340541245274 2000-01-01 9.02328852057384 2001-01-01 9.43444642655261 2002-01-01 9.05289326394019 2003-01-01 8.54027401246746 2004-01-01 8.99538036381609 2005-01-01 7.99410870715039 2006-01-01 6.59467082312774 2007-01-01 5.48377362330933 2008-01-01 4.73901042021013 2009-01-01 5.97891116442776 2010-01-01 7.17869656429246 2011-01-01 6.76872273953998 2012-01-01 6.99396776640823 2013-01-01 7.13711465956975