Year	Ratio
1971-01-01	0.988919973373413
1972-01-01	0.988619983196259
1973-01-01	1.010550022125240
1974-01-01	0.998910009860992
1975-01-01	0.996410012245178
1976-01-01	0.996640026569366
1977-01-01	0.993610024452209
1978-01-01	0.993589997291565
1979-01-01	0.999419987201691
1980-01-01	0.995500028133392
1981-01-01	0.996389985084534
1982-01-01	0.997799992561340
1983-01-01	1.005859971046450
1984-01-01	1.009479999542240
1985-01-01	1.010789990425110
1986-01-01	1.010149955749510
1987-01-01	1.015409946441650
1988-01-01	1.017289996147160
1989-01-01	1.017950057983400
1990-01-01	1.018200039863590
1991-01-01	1.023640036582950
1992-01-01	1.020169973373410
1993-01-01	0.997009992599487
1994-01-01	0.994669973850250
1995-01-01	0.993799984455109
1996-01-01	0.994390010833740
1999-01-01	0.992150008678436
2000-01-01	0.994490027427673
2001-01-01	0.993770003318787
2002-01-01	0.993160009384155
2003-01-01	0.991389989852905
2004-01-01	0.996460020542145
2005-01-01	0.995540022850037
2006-01-01	0.994220018386841
2007-01-01	0.996930003166199
2008-01-01	0.997669994831085
2009-01-01	0.996720016002655
2010-01-01	0.997659981250763
2011-01-01	0.997969985008240
2012-01-01	0.995850026607513
2013-01-01	1.001289963722230
2014-01-01	0.999710023403168
2015-01-01	0.998310029506683