Year Percent 1980-01-01 4.4634900000000000 1981-01-01 2.6920100000000000 1982-01-01 0.9297620000000001 1983-01-01 2.2235600000000000 1984-01-01 2.4267700000000000 1985-01-01 1.0573100000000000 1986-01-01 3.3459199999999996 1987-01-01 9.5496199999999990 1988-01-01 9.8359800000000010 1989-01-01 9.7731800000000000 1990-01-01 9.6258699999999990 1991-01-01 6.9233600000000010 1992-01-01 9.4341800000000000 1993-01-01 11.4925000000000000 1994-01-01 16.3708000000000000 1995-01-01 19.8236000000000000 1996-01-01 24.1902000000000000 1997-01-01 26.3003000000000000 1998-01-01 17.8491000000000000 1999-01-01 18.3049000000000000 2000-01-01 15.2528000000000000 2001-01-01 6.2270199999999996 2002-01-01 3.1582300000000000 2003-01-01 2.6739700000000000 2004-01-01 3.0542100000000000 2005-01-01 4.1768700000000000 2006-01-01 6.1152000000000000 2007-01-01 11.4182000000000000 2008-01-01 11.1745000000000000 2009-01-01 7.6776399999999990 2010-01-01 9.3442000000000000 2011-01-01 11.3569000000000000 2012-01-01 12.7875000000000000 2013-01-01 14.6779999999999990 2014-01-01 14.9934000000000000 2015-01-01 13.5861000000000000 2016-01-01 11.8815000000000000 2017-01-01 10.7732000000000000