Year	Ratio
1971-01-01	0.483980000019073
1972-01-01	0.498030006885529
1973-01-01	0.558629989624023
1974-01-01	0.586179971694946
1975-01-01	0.596010029315948
1976-01-01	0.618740022182465
1977-01-01	0.631439983844757
1978-01-01	0.627950012683868
1979-01-01	0.642019987106323
1980-01-01	0.640579998493195
1981-01-01	0.641770005226135
1982-01-01	0.612020015716553
1983-01-01	0.628390014171600
1984-01-01	0.649290025234222
1985-01-01	0.674700021743774
1986-01-01	0.701349973678589
1987-01-01	0.731769979000092
1988-01-01	0.775650024414063
1989-01-01	0.791819989681244
1990-01-01	0.798389971256256
1991-01-01	0.832859992980957
1992-01-01	0.812510013580322
1993-01-01	0.813629984855652
1995-01-01	0.794849991798401
1996-01-01	0.842809975147247
1997-01-01	0.835020005702972
1998-01-01	0.807299971580505
1999-01-01	0.781790018081665
2000-01-01	0.789799988269806
2001-01-01	0.787119984626770
2002-01-01	0.771040022373199
2003-01-01	0.790229976177216
2004-01-01	0.816100001335144
2005-01-01	0.840650022029877
2006-01-01	0.891260027885437
2007-01-01	0.910340011119843
2008-01-01	0.930509984493256
2009-01-01	0.946739971637726
2010-01-01	0.965910017490387
2011-01-01	0.981989979743958
2012-01-01	0.991249978542328
2013-01-01	0.995899975299835
2014-01-01	1.010910034179690
2015-01-01	1.010130047798160
2016-01-01	1.006160020828250