Year	Ratio
1971-01-01	0.411460012197495
1972-01-01	0.434439986944199
1973-01-01	0.470990002155304
1974-01-01	0.487560003995895
1975-01-01	0.514909982681274
1976-01-01	0.529399991035461
1977-01-01	0.545870006084442
1978-01-01	0.580889999866486
1979-01-01	0.614030003547668
1980-01-01	0.639039993286133
1981-01-01	0.656840026378632
1982-01-01	0.681900024414063
1984-01-01	0.714760005474091
1985-01-01	0.726300001144409
1986-01-01	0.742169976234436
1987-01-01	0.737670004367828
1988-01-01	0.744270026683807
1989-01-01	0.758849978446960
1990-01-01	0.774039983749390
1991-01-01	0.797720015048981
1992-01-01	0.817049980163574
1993-01-01	0.836489975452423
1994-01-01	0.862020015716553
1995-01-01	0.885209977626801
1996-01-01	0.901170015335083
1997-01-01	0.954689979553223
1999-01-01	1.011150002479550
2000-01-01	1.047449946403500
2001-01-01	1.063380002975460
2002-01-01	1.063670039176940
2003-01-01	1.087260007858280
2004-01-01	1.090620040893550
2005-01-01	1.095289945602420
2006-01-01	1.093909978866580
2007-01-01	1.080890059471130
2008-01-01	1.037909984588620
2009-01-01	1.010489940643310
2010-01-01	1.035429954528810
2011-01-01	1.037989974021910