Year Percent 1985-01-01 27.8587000000000000000 1986-01-01 23.0800000000000000000 1987-01-01 16.5283000000000000000 1988-01-01 15.0279999999999990000 1989-01-01 15.5040000000000010000 1990-01-01 10.4803000000000000000 1991-01-01 15.9987000000000000000 1992-01-01 20.3625000000000000000 1993-01-01 22.9665000000000000000 1994-01-01 23.6970000000000000000 1995-01-01 21.2387000000000000000 1996-01-01 12.3012000000000000000 1997-01-01 5.4791300000000005000 1998-01-01 5.9891800000000000000 1999-01-01 3.8557000000000000000 2000-01-01 2.1785400000000004000 2001-01-01 0.7719030000000000000 2002-01-01 0.2227770000000000000 2003-01-01 0.0911840000000000000 2004-01-01 0.0355269999999999960 2005-01-01 0.0124580000000000000 2006-01-01 0.0026270000000000000 2007-01-01 0.0026270000000000000 2008-01-01 0.0025329999999999997 2009-01-01 0.0077890000000000000 2010-01-01 0.0098580000000000000 2011-01-01 0.0110580000000000000 2012-01-01 0.0143400000000000000 2013-01-01 0.0204800000000000000 2014-01-01 1.7598700000000000000 2015-01-01 6.2268300000000005000 2016-01-01 9.4593200000000000000