Year Percent 1980-01-01 0.8179489999999999 1981-01-01 1.1578600000000001 1982-01-01 1.2166400000000000 1983-01-01 3.0679200000000000 1984-01-01 4.7579900000000000 1985-01-01 5.2958900000000000 1986-01-01 5.9691300000000010 1987-01-01 4.6972400000000000 1988-01-01 4.1407300000000005 1989-01-01 3.8665100000000000 1990-01-01 3.9810800000000004 1991-01-01 3.7581500000000000 1992-01-01 2.7695100000000000 1993-01-01 1.3647000000000000 1994-01-01 0.3613240000000000 1995-01-01 0.1382350000000000 1996-01-01 0.1974970000000000 1997-01-01 1.7421500000000000 1998-01-01 3.4945800000000005 1999-01-01 2.3154500000000000 2000-01-01 3.8251199999999996 2001-01-01 4.0386100000000000 2002-01-01 3.1182100000000000 2003-01-01 2.6288600000000000 2004-01-01 3.3730700000000000 2005-01-01 3.5517199999999995 2006-01-01 3.3271300000000004 2007-01-01 2.1604000000000000 2008-01-01 1.3249100000000000 2009-01-01 1.1267399999999999 2010-01-01 2.3321600000000000 2011-01-01 2.0291400000000000 2012-01-01 2.2534099999999997 2013-01-01 3.1007000000000000 2014-01-01 6.3599600000000000 2015-01-01 4.8337800000000000 2016-01-01 6.5196700000000000