Year	Ratio
1971-01-01	0.457830011844635
1972-01-01	0.555920004844666
1973-01-01	0.456349998712540
1974-01-01	0.453960001468658
1975-01-01	0.449759989976883
1976-01-01	0.501590013504028
1977-01-01	0.521070003509521
1978-01-01	0.508889973163605
1979-01-01	0.523199975490570
1981-01-01	0.494989991188049
1982-01-01	0.487789988517761
1983-01-01	0.479090005159378
1984-01-01	0.475510001182556
1985-01-01	0.455870002508163
1986-01-01	0.459899991750717
1987-01-01	0.440959990024567
1988-01-01	0.445730000734329
1989-01-01	0.442820012569427
1990-01-01	0.446759998798370
1991-01-01	0.459859997034073
1992-01-01	0.459969997406006
1993-01-01	0.464830011129379
1994-01-01	0.486369997262955
1995-01-01	0.505639970302582
1996-01-01	0.525650024414063
1997-01-01	0.564050018787384
1998-01-01	0.589680016040802
1999-01-01	0.620679974555969
2000-01-01	0.668640017509460
2001-01-01	0.704789996147156
2002-01-01	0.729470014572144
2003-01-01	0.755550026893616
2004-01-01	0.776790022850037
2005-01-01	0.801840007305145
2006-01-01	0.826430022716522
2007-01-01	0.840579986572266
2008-01-01	0.837989985942841
2009-01-01	0.841300010681152
2010-01-01	0.823689997196198
2011-01-01	0.851740002632141
2012-01-01	0.842530012130737
2013-01-01	0.843689978122711
2014-01-01	0.846939980983734