Year Percent 1960-01-01 63.63640000000000 1961-01-01 66.27150000000000 1962-01-01 62.47830000000000 1963-01-01 58.81660000000000 1964-01-01 63.30710000000000 1965-01-01 66.87600000000000 1966-01-01 70.14090000000000 1967-01-01 68.50430000000000 1968-01-01 64.44620000000000 1969-01-01 64.80000000000000 1970-01-01 66.47430000000000 1971-01-01 64.22620000000000 1972-01-01 82.83350000000000 1973-01-01 120.85300000000000 1974-01-01 134.63000000000000 1975-01-01 140.06300000000000 1976-01-01 135.66700000000000 1977-01-01 133.24100000000000 1978-01-01 195.05300000000000 1979-01-01 332.39099999999996 1980-01-01 393.74600000000000 1981-01-01 126.98200000000001 1982-01-01 78.13990000000000 1983-01-01 74.02880000000000 1984-01-01 66.12070000000000 1985-01-01 66.12270000000000 1986-01-01 74.25920000000000 1987-01-01 83.38670000000000 1988-01-01 86.57410000000000 1989-01-01 87.84290000000000 1990-01-01 91.62940000000000 1991-01-01 96.38700000000000 1992-01-01 98.47770000000000 1993-01-01 103.00100000000000 1994-01-01 105.48800000000000 1995-01-01 102.81900000000000 1996-01-01 98.75890000000000 1997-01-01 95.97960000000000 1998-01-01 95.12820000000000 1999-01-01 93.99620000000000 2000-01-01 95.82810000000000 2001-01-01 99.34890000000000 2002-01-01 101.14200000000001 2003-01-01 100.38700000000000 2004-01-01 99.40299999999999 2005-01-01 100.28000000000000 2006-01-01 100.44100000000000 2007-01-01 104.01000000000000 2008-01-01 107.48400000000000 2009-01-01 104.66200000000000 2010-01-01 103.51299999999999 2011-01-01 102.20299999999999 2012-01-01 100.68000000000000 2013-01-01 98.66600000000000 2014-01-01 93.67910000000000 2015-01-01 91.51460000000000 2016-01-01 89.12490000000000