Year Percent 1980-01-01 5.2657099999999994 1981-01-01 5.3778100000000000 1982-01-01 5.4081700000000000 1983-01-01 5.3696800000000010 1984-01-01 5.7529100000000000 1985-01-01 6.4934300000000000 1986-01-01 7.3029500000000000 1987-01-01 7.1415300000000000 1988-01-01 6.8686600000000000 1989-01-01 6.8004200000000000 1990-01-01 6.4419500000000000 1991-01-01 6.0374200000000000 1992-01-01 3.5644000000000000 1993-01-01 3.3487000000000000 1994-01-01 3.1539700000000000 1995-01-01 1.8350900000000000 1996-01-01 1.4059400000000000 1997-01-01 2.9734300000000000 1998-01-01 2.2398500000000000 1999-01-01 3.4604800000000004 2000-01-01 5.3045599999999995 2001-01-01 4.6836000000000000 2002-01-01 4.6906500000000000 2003-01-01 4.7028300000000005 2004-01-01 5.5226100000000000 2005-01-01 5.4229600000000000 2006-01-01 5.7014400000000000 2007-01-01 5.6504199999999996 2008-01-01 4.5250400000000000 2009-01-01 4.9938300000000000 2010-01-01 4.4732800000000000 2011-01-01 5.1889800000000000 2012-01-01 4.9061699999999995 2013-01-01 5.2891200000000000 2014-01-01 6.9773500000000000 2015-01-01 8.2876000000000000 2016-01-01 9.3452300000000000