Year Ratio 1971-01-01 0.983020007610321 1972-01-01 0.987070024013519 1973-01-01 0.990769982337952 1974-01-01 0.995000004768372 1975-01-01 0.999870002269745 1976-01-01 1.006510019302370 1977-01-01 1.009850025177000 1978-01-01 1.011780023574830 1979-01-01 1.006170034408570 1980-01-01 1.001250028610230 1981-01-01 1.005210041999820 1982-01-01 1.002249956130980 1983-01-01 1.005380034446720 1984-01-01 1.005439996719360 1985-01-01 1.004510045051570 1986-01-01 1.004850029945370 1987-01-01 1.002750039100650 1988-01-01 1.003690004348750 1989-01-01 1.001449942588810 1990-01-01 0.996879994869232 1991-01-01 0.997659981250763 1992-01-01 1.002689957618710 1993-01-01 1.004089951515200 1994-01-01 1.002730011940000 1995-01-01 1.019369959831240 1996-01-01 1.004179954528810 1997-01-01 1.005489945411680 1998-01-01 1.003509998321530 1999-01-01 1.001680016517640 2000-01-01 0.999970018863678 2001-01-01 0.999130010604858 2002-01-01 0.990109980106354 2003-01-01 0.986299991607666 2004-01-01 0.976119995117188 2005-01-01 0.978810012340546 2006-01-01 0.978079974651337 2007-01-01 0.980289995670319 2010-01-01 0.981700003147125 2011-01-01 0.983460009098053 2012-01-01 0.982490003108978 2013-01-01 0.983489990234375 2014-01-01 0.988160014152527 2015-01-01 0.990800023078918