Year Percent 1980-01-01 0.583476000000000000 1981-01-01 0.626300000000000000 1982-01-01 0.578066000000000000 1983-01-01 0.585063000000000000 1984-01-01 0.750390000000000000 1985-01-01 1.946520000000000000 1986-01-01 1.693140000000000000 1987-01-01 1.598190000000000000 1988-01-01 1.563710000000000000 1989-01-01 1.444760000000000000 1990-01-01 0.701857000000000000 1991-01-01 0.465517000000000000 1992-01-01 0.654291000000000000 1993-01-01 0.621208000000000000 1994-01-01 0.836537000000000100 1995-01-01 0.770666000000000000 1996-01-01 0.907258000000000000 1997-01-01 1.278590000000000000 1998-01-01 1.831220000000000000 1999-01-01 1.568270000000000000 2000-01-01 1.573100000000000000 2001-01-01 1.772950000000000000 2002-01-01 1.997459999999999800 2003-01-01 1.780270000000000000 2004-01-01 1.951309999999999900 2005-01-01 1.592690000000000000 2006-01-01 1.323170000000000200 2007-01-01 0.441866000000000000 2008-01-01 0.320728000000000000 2009-01-01 0.209616000000000000 2010-01-01 0.196144000000000000 2011-01-01 0.103455999999999990 2012-01-01 0.086235000000000000 2013-01-01 0.022433000000000000 2014-01-01 0.020534999999999998 2015-01-01 0.025180000000000000 2016-01-01 0.062641000000000000