Year Percent 1980-01-01 9.8920700000000000 1981-01-01 13.2722000000000000 1982-01-01 11.8426000000000000 1983-01-01 14.9520000000000000 1984-01-01 13.3921000000000000 1985-01-01 10.7174000000000000 1986-01-01 9.8177800000000000 1987-01-01 10.9467000000000000 1988-01-01 10.4774000000000000 1989-01-01 11.5260000000000000 1990-01-01 7.5821500000000000 1991-01-01 7.3536899999999990 1992-01-01 5.5579400000000000 1993-01-01 10.0409000000000000 1994-01-01 10.3118000000000000 1995-01-01 8.9431600000000000 1996-01-01 7.9220000000000010 1997-01-01 7.2303200000000000 1998-01-01 9.6890300000000000 1999-01-01 5.7973000000000000 2000-01-01 6.5278000000000000 2001-01-01 8.5496300000000000 2002-01-01 7.1631899999999990 2003-01-01 6.6386400000000000 2004-01-01 6.7616800000000000 2005-01-01 9.4468100000000010 2006-01-01 9.4994000000000000 2007-01-01 8.6293700000000000 2008-01-01 7.7222000000000000 2009-01-01 11.0515000000000000 2010-01-01 9.1885100000000000 2011-01-01 9.2227800000000000 2012-01-01 9.0001100000000010 2013-01-01 8.1017900000000000 2014-01-01 8.4964800000000000 2015-01-01 7.3767900000000000 2016-01-01 6.7473600000000005