Year Percent 1960-01-01 198.50900000000001 1961-01-01 210.04900000000000 1962-01-01 216.77599999999998 1963-01-01 223.09000000000000 1964-01-01 199.32200000000000 1965-01-01 174.42300000000000 1966-01-01 170.57900000000000 1967-01-01 175.37800000000000 1968-01-01 164.36700000000002 1969-01-01 142.88000000000000 1970-01-01 136.02900000000000 1971-01-01 146.92100000000000 1972-01-01 170.65000000000000 1973-01-01 186.07000000000000 1974-01-01 175.29000000000000 1975-01-01 176.91400000000002 1976-01-01 169.42800000000000 1977-01-01 153.41200000000000 1978-01-01 156.55800000000000 1979-01-01 182.44099999999997 1980-01-01 219.25900000000001 1981-01-01 231.75099999999998 1982-01-01 230.89600000000000 1983-01-01 234.54900000000000 1984-01-01 217.37500000000000 1985-01-01 182.04500000000000 1986-01-01 165.96700000000000 1987-01-01 173.49900000000002 1988-01-01 180.39700000000002 1989-01-01 177.93900000000002 1990-01-01 181.74599999999998 1991-01-01 182.50700000000000 1992-01-01 169.93800000000000 1993-01-01 159.72400000000000 1994-01-01 128.99400000000000 1995-01-01 101.87799999999999 1996-01-01 101.44200000000001 1997-01-01 105.97500000000000 1998-01-01 112.33700000000000 1999-01-01 108.11200000000001 2000-01-01 107.17600000000000 2001-01-01 114.13200000000000 2002-01-01 106.37299999999999 2003-01-01 94.37760000000000 2004-01-01 92.09970000000000 2005-01-01 91.31210000000000 2006-01-01 88.66320000000000 2007-01-01 87.19410000000000 2008-01-01 88.09620000000000 2009-01-01 88.57740000000000 2010-01-01 84.34350000000000 2011-01-01 74.11820000000000 2012-01-01 69.38780000000000 2013-01-01 73.97240000000000 2014-01-01 77.33400000000000 2015-01-01 80.87580000000000 2016-01-01 84.96660000000000