Year Percent 1998-01-01 6.600000000000000 1999-01-01 6.600000000000000 2000-01-01 6.400000000000000 2001-01-01 6.200000000000000 2002-01-01 6.300000000000000 2003-01-01 6.900000000000000 2004-01-01 6.800000000000000 2005-01-01 7.500000000000000 2006-01-01 9.100000000000000 2007-01-01 8.900000000000000 2008-01-01 8.500000000000000 2009-01-01 7.200000000000000 2010-01-01 7.300000000000000 2011-01-01 7.604019999999999