Year Percent 1980-01-01 4.4092000000000000 1981-01-01 5.3754400000000000 1982-01-01 5.9375500000000000 1983-01-01 7.3750800000000005 1984-01-01 11.5975000000000000 1985-01-01 12.4259999999999980 1986-01-01 15.1613000000000000 1987-01-01 16.2684000000000000 1988-01-01 13.7834000000000000 1989-01-01 13.7756000000000000 1990-01-01 13.0447000000000000 1991-01-01 10.3086000000000000 1992-01-01 7.4473000000000000 1993-01-01 14.5019000000000000 1994-01-01 12.3476000000000000 1995-01-01 9.9401200000000000 1996-01-01 9.2322200000000000 1997-01-01 9.2181900000000000 1998-01-01 7.5072000000000000 1999-01-01 6.7543700000000000 2000-01-01 6.5250000000000000 2001-01-01 5.6944099999999995 2002-01-01 4.2992400000000000 2003-01-01 3.7701000000000000 2004-01-01 2.7584299999999997 2005-01-01 2.6553800000000000 2006-01-01 2.3118800000000000 2007-01-01 2.1457000000000000 2008-01-01 3.4235500000000000 2009-01-01 6.8076300000000005 2010-01-01 5.8757300000000000 2011-01-01 6.3562199999999995 2012-01-01 5.3599800000000000 2013-01-01 4.1331300000000000 2014-01-01 3.1535300000000000 2015-01-01 2.3764900000000000 2016-01-01 0.9151520000000001