Year	Ratio
1971-01-01	0.353329986333847
1972-01-01	0.371809989213943
1973-01-01	0.387860000133514
1974-01-01	0.411089986562729
1975-01-01	0.439639985561371
1976-01-01	0.459679991006851
1977-01-01	0.489259988069534
1978-01-01	0.511250019073486
1979-01-01	0.537670016288757
1980-01-01	0.571009993553162
1981-01-01	0.589659988880157
1982-01-01	0.601570010185242
1983-01-01	0.618690013885498
1984-01-01	0.635500013828278
1985-01-01	0.661970019340515
1986-01-01	0.682380020618439
1987-01-01	0.688560009002686
1988-01-01	0.704020023345947
1989-01-01	0.707459986209869
1990-01-01	0.727299988269806
1991-01-01	0.735589981079102
1992-01-01	0.762549996376038
1993-01-01	0.803290009498596
1994-01-01	0.811659991741180
1995-01-01	0.832570016384125
1996-01-01	0.872919976711273
1997-01-01	0.898639976978302
1998-01-01	0.899550020694733
1999-01-01	0.916689991950989
2000-01-01	0.919059991836548
2001-01-01	0.904030025005341
2002-01-01	0.911970019340515
2003-01-01	0.938149988651276
2004-01-01	0.948189973831177
2005-01-01	0.957059979438782
2006-01-01	0.970539987087250
2007-01-01	0.990520000457764
2008-01-01	0.998380005359650
2009-01-01	1.004040002822880
2010-01-01	1.001909971237180
2011-01-01	0.997900009155273
2012-01-01	1.003219962120060
2013-01-01	1.000779986381530