Year Percent 1976-01-01 116.58800000000000 1977-01-01 110.96700000000001 1978-01-01 97.99170000000000 1979-01-01 74.79950000000000 1980-01-01 61.11730000000000 1981-01-01 49.04270000000000 1982-01-01 55.41620000000000 1983-01-01 66.31740000000000 1984-01-01 63.74700000000000 1985-01-01 77.98160000000000 1986-01-01 98.29520000000000 1987-01-01 97.26660000000000 1988-01-01 87.27770000000000 1989-01-01 103.52000000000000 1990-01-01 115.09200000000001 1991-01-01 104.24000000000000 1992-01-01 96.02540000000000 1993-01-01 93.55360000000000 1994-01-01 86.23760000000000 1995-01-01 89.52090000000000 1996-01-01 96.83010000000000 1997-01-01 94.72490000000000 1998-01-01 94.49270000000000 1999-01-01 90.47740000000000 2000-01-01 82.55200000000000 2001-01-01 87.46230000000000 2002-01-01 91.73260000000000 2003-01-01 85.88670000000000 2004-01-01 83.80220000000000 2005-01-01 87.62510000000000 2006-01-01 84.49390000000000 2007-01-01 85.22930000000000 2008-01-01 86.23210000000000 2009-01-01 86.21720000000000 2010-01-01 80.00490000000000 2011-01-01 73.99250000000000 2012-01-01 71.97720000000000 2013-01-01 66.50520000000000 2014-01-01 64.23430000000000 2015-01-01 67.61140000000000 2016-01-01 70.10860000000000