Year Percent 1964-01-01 69.32270000000000 1965-01-01 66.64770000000000 1966-01-01 71.52460000000000 1967-01-01 80.36430000000000 1968-01-01 80.55310000000000 1969-01-01 70.25010000000000 1970-01-01 70.01720000000000 1971-01-01 76.98000000000000 1972-01-01 78.63500000000000 1973-01-01 79.16860000000000 1974-01-01 113.12600000000000 1975-01-01 104.34200000000001 1976-01-01 58.57500000000000 1977-01-01 54.43920000000000 1978-01-01 66.75330000000000 1979-01-01 103.40000000000000 1980-01-01 124.53200000000001 1981-01-01 147.08600000000000 1982-01-01 151.25900000000000 1983-01-01 108.02500000000000 1984-01-01 75.46410000000000 1985-01-01 51.37010000000000 1986-01-01 53.19920000000000 1987-01-01 60.74350000000000 1988-01-01 65.62880000000000 1989-01-01 72.77220000000000 1990-01-01 81.67650000000000 1991-01-01 92.42140000000000 1992-01-01 96.93290000000000 1993-01-01 111.90500000000000 1994-01-01 112.18200000000000 1995-01-01 99.60340000000000 1996-01-01 101.51400000000000 1997-01-01 102.54700000000001 1998-01-01 119.41700000000000 1999-01-01 125.12700000000001 2000-01-01 129.86500000000000 2001-01-01 137.17700000000002 2002-01-01 131.17000000000000 2003-01-01 118.97500000000000 2004-01-01 107.24700000000001 2005-01-01 93.51060000000000 2006-01-01 80.56970000000000 2007-01-01 76.93690000000000 2008-01-01 71.28370000000000 2009-01-01 70.62560000000000 2010-01-01 78.84670000000000 2011-01-01 92.36430000000000 2012-01-01 100.38500000000000 2013-01-01 95.71430000000000 2014-01-01 91.23420000000000 2015-01-01 89.00320000000000 2016-01-01 88.74530000000000