Year	Ratio
1971-01-01	0.632560014724731
1972-01-01	0.701560020446777
1974-01-01	0.694329977035522
1975-01-01	0.687089979648590
1976-01-01	0.657500028610229
1977-01-01	0.790960013866425
1978-01-01	0.833630025386810
1979-01-01	0.811349987983704
1980-01-01	0.818889975547791
1981-01-01	0.886929988861084
1982-01-01	0.899489998817444
1983-01-01	0.899789988994598
1984-01-01	0.919809997081757
1985-01-01	0.902350008487701
1986-01-01	0.946259975433350
1987-01-01	0.957740008831024
1988-01-01	0.966639995574951
1989-01-01	0.982280015945435
1990-01-01	0.989530026912689
1991-01-01	0.998260021209717
1992-01-01	0.967469990253448
1993-01-01	0.988839983940125
1994-01-01	1.001060009002690
1995-01-01	1.006129980087280
1996-01-01	0.999689996242523
1997-01-01	0.998109996318817
1998-01-01	1.009899973869320
1999-01-01	1.026569962501530
2000-01-01	1.041039943695070
2001-01-01	1.056370019912720
2002-01-01	1.074489951133730
2003-01-01	1.099830031394960
2004-01-01	1.088459968566890
2005-01-01	1.088840007781980
2006-01-01	1.093709945678710
2007-01-01	1.093880057334900
2008-01-01	1.096199989318850
2009-01-01	1.097419977188110
2010-01-01	1.086940050125120
2011-01-01	1.077059984207150
2012-01-01	1.071210026741030
2013-01-01	1.061699986457820
2014-01-01	1.062469959259030
2015-01-01	1.074139952659610
2016-01-01	1.086060047149660