Year Percent 1980-01-01 1.67710999999999990 1981-01-01 2.44588000000000000 1982-01-01 2.51335000000000000 1983-01-01 2.40178000000000000 1984-01-01 1.86872000000000020 1985-01-01 0.21996600000000000 1986-01-01 0.25310500000000000 1987-01-01 0.30853900000000000 1988-01-01 0.23376100000000002 1989-01-01 0.21869400000000000 1990-01-01 8.81657000000000000 1991-01-01 7.21808999999999900 1992-01-01 6.27863000000000100 1993-01-01 5.62284000000000000 1994-01-01 5.29273000000000100 1995-01-01 4.79140000000000000 1996-01-01 4.35935000000000000 1997-01-01 3.87413000000000000 1998-01-01 3.01885000000000000 1999-01-01 2.89356000000000000 2000-01-01 2.68952000000000000 2001-01-01 2.36317000000000000 2002-01-01 2.14595999999999960 2003-01-01 1.40856000000000000 2004-01-01 0.51096200000000000 2005-01-01 0.47335200000000005 2006-01-01 0.42568300000000000 2007-01-01 0.35501600000000000 2008-01-01 0.30884500000000000 2009-01-01 0.32064300000000000 2010-01-01 0.26252800000000004 2011-01-01 0.81122800000000000 2012-01-01 1.26429000000000000 2013-01-01 5.11498000000000000 2014-01-01 4.87691000000000000 2015-01-01 4.57791000000000000 2016-01-01 5.20451000000000000