Year Percent 1982-01-01 0.34180300000000000 1983-01-01 0.33352400000000000 1984-01-01 0.37409400000000000 1985-01-01 0.65128300000000000 1986-01-01 1.27180000000000000 1987-01-01 1.56149000000000000 1988-01-01 1.95508000000000000 1989-01-01 2.14221000000000000 1990-01-01 1.65810999999999980 1991-01-01 1.18859000000000000 1992-01-01 0.84652900000000010 1993-01-01 0.96207099999999990 1994-01-01 1.32721000000000000 1995-01-01 1.18555000000000000 1996-01-01 1.62529000000000000 1997-01-01 3.64068000000000000 1998-01-01 6.25831999999999900 1999-01-01 5.47418000000000050 2000-01-01 4.78926000000000000 2001-01-01 3.81844000000000030 2002-01-01 1.61492000000000010 2003-01-01 1.10351000000000000 2004-01-01 1.02007999999999990 2005-01-01 0.84024400000000010 2006-01-01 0.55570500000000000 2007-01-01 0.49780200000000000 2008-01-01 1.85065999999999970 2009-01-01 1.94045999999999990 2010-01-01 0.42021899999999995 2011-01-01 0.25995900000000000 2012-01-01 0.20232000000000000 2013-01-01 0.19344800000000000 2014-01-01 0.17397300000000000 2015-01-01 0.16393600000000000 2016-01-01 0.14153300000000000 2017-01-01 0.13271400000000000