Year Percent 1986-01-01 39.09 1987-01-01 42.36 1988-01-01 46.77 1989-01-01 26.87 1990-01-01 62.72 1991-01-01 59.87 1992-01-01 67.77 1993-01-01 69.63 1994-01-01 92.04 1995-01-01 106.31 1996-01-01 73.99 1997-01-01 78.04 1998-01-01 78.97 1999-01-01 69.97 2000-01-01 183.20 2001-01-01 59.00 2002-01-01 44.00 2003-01-01 26.00 2004-01-01 18.69 2005-01-01 13.57 2006-01-01 17.50 2007-01-01 15.96 2008-01-01 15.63 2009-01-01 6.50 2010-01-01 1.63 2011-01-01 5.00 2012-01-01 5.00 2013-01-01 3.50 2014-01-01 7.50 2015-01-01 7.25 2016-01-01 7.25 2017-01-01 7.25