Year Percent 1977-01-01 0.013479000000000000 1978-01-01 0.013704000000000000 1979-01-01 0.023243000000000000 1980-01-01 0.015194000000000000 1981-01-01 0.013022999999999998 1982-01-01 0.008483000000000000 1983-01-01 0.008516000000000000 1984-01-01 0.175549000000000000 1985-01-01 0.204047000000000000 1986-01-01 0.229986000000000020 1987-01-01 0.229986000000000020 1988-01-01 0.229986000000000020 1989-01-01 0.229986000000000020 1990-01-01 0.229986000000000020 1991-01-01 0.229986000000000020 1992-01-01 0.229986000000000020 1993-01-01 0.229986000000000020 1994-01-01 0.229986000000000020 1995-01-01 9.907500000000000000 1996-01-01 8.160739999999999000 1997-01-01 10.819800000000000000 1998-01-01 16.420800000000000000 1999-01-01 16.057700000000000000 2000-01-01 13.356400000000000000 2001-01-01 12.423800000000000000 2002-01-01 9.693389999999999000 2003-01-01 0.125111000000000000 2004-01-01 0.176624000000000000 2005-01-01 0.352250000000000000 2006-01-01 1.096310000000000100 2007-01-01 1.968680000000000000 2008-01-01 1.787810000000000000 2009-01-01 2.653710000000000000 2010-01-01 2.340180000000000000 2011-01-01 1.828860000000000000 2012-01-01 1.776560000000000000 2013-01-01 2.069379999999999800 2014-01-01 2.274340000000000000 2015-01-01 2.038030000000000000 2016-01-01 6.976690000000000000