Year Percent 1980-01-01 0.8709030000000001 1981-01-01 0.8939500000000000 1982-01-01 0.9521090000000000 1983-01-01 1.1128100000000000 1984-01-01 1.1649600000000000 1985-01-01 3.3626199999999997 1986-01-01 3.0762000000000000 1987-01-01 2.8805000000000000 1988-01-01 2.6418600000000000 1989-01-01 2.3213200000000000 1990-01-01 1.5976299999999999 1991-01-01 1.1050000000000000 1992-01-01 1.2458200000000001 1993-01-01 3.5295900000000002 1994-01-01 4.9007700000000000 1995-01-01 5.0188000000000000 1996-01-01 7.2795100000000000 1997-01-01 9.6465300000000000 1998-01-01 13.2588000000000000 1999-01-01 10.9708000000000000 2000-01-01 10.2062000000000000 2001-01-01 8.5625700000000000 2002-01-01 7.5521400000000000 2003-01-01 6.0224800000000010 2004-01-01 5.3346500000000000 2005-01-01 5.4334100000000000 2006-01-01 5.0366400000000000 2007-01-01 3.4739900000000000 2008-01-01 3.1814100000000000 2009-01-01 2.7517000000000000 2010-01-01 2.6913800000000000 2011-01-01 2.7311300000000000 2012-01-01 4.0885700000000000 2013-01-01 4.3472200000000000 2014-01-01 5.1784600000000000 2015-01-01 4.8731300000000010 2016-01-01 4.9322700000000000