Year Percent 1973-01-01 5.66028000000000000 1974-01-01 5.39418000000000000 1975-01-01 6.71596000000000100 1976-01-01 6.39462000000000000 1977-01-01 6.09840999999999900 1978-01-01 5.81198000000000000 1979-01-01 5.59261000000000000 1980-01-01 5.52349000000000000 1981-01-01 6.08862000000000000 1982-01-01 5.94670999999999950 1983-01-01 6.15506000000000000 1984-01-01 6.87898999999999900 1985-01-01 7.69703000000000100 1986-01-01 8.66585000000000000 1987-01-01 9.66551000000000100 1988-01-01 10.52099999999999900 1989-01-01 9.82258000000000000 1990-01-01 9.66293999999999900 1991-01-01 9.16602000000000000 1992-01-01 9.66276000000000000 1993-01-01 8.69216999999999900 1994-01-01 6.89476999999999900 1995-01-01 6.73371000000000000 1996-01-01 6.72310000000000000 1997-01-01 3.89124000000000030 1998-01-01 1.29349000000000000 1999-01-01 1.35374000000000000 2000-01-01 1.60822999999999980 2001-01-01 1.81125000000000000 2002-01-01 1.94058000000000000 2003-01-01 2.16085000000000000 2004-01-01 2.08129000000000000 2005-01-01 1.92057000000000000 2006-01-01 1.92430000000000000 2007-01-01 1.13558000000000000 2008-01-01 0.36265500000000000 2009-01-01 0.42196700000000000 2010-01-01 0.44784500000000000 2011-01-01 0.37615700000000000 2012-01-01 0.34285800000000000 2013-01-01 0.33325100000000000 2014-01-01 0.35678000000000004 2015-01-01 0.42238600000000000