Year	Ratio
1970-01-01	0.861209988594055
1971-01-01	0.840799987316132
1972-01-01	0.844439983367920
1973-01-01	0.829439997673035
1974-01-01	0.809899985790253
1975-01-01	0.857029974460602
1976-01-01	0.881079971790314
1977-01-01	0.880230009555817
1978-01-01	0.879249989986420
1981-01-01	0.876940011978149
1982-01-01	0.900579988956451
1983-01-01	0.944090008735657
1984-01-01	0.948379993438721
1985-01-01	0.952170014381409
1986-01-01	0.943560004234314
1987-01-01	0.953220009803772
1988-01-01	0.952600002288818
1989-01-01	0.966799974441528
1990-01-01	0.969020009040833
1991-01-01	0.984120011329651
1992-01-01	0.992760002613068
1993-01-01	0.975660026073456
1994-01-01	0.970759987831116
1995-01-01	0.965810000896454
1996-01-01	0.964890003204346
1997-01-01	0.964359998703003
1998-01-01	0.943740010261536
1999-01-01	0.971159994602203
2000-01-01	0.971949994564056
2001-01-01	0.977039992809296
2002-01-01	0.978349983692169
2003-01-01	0.982219994068146
2004-01-01	0.985669970512390
2005-01-01	0.969299972057343
2006-01-01	0.969950020313263
2007-01-01	0.964950025081635
2008-01-01	0.984300017356873
2009-01-01	0.982500016689301
2010-01-01	1.038920044898990
2011-01-01	1.042559981346130
2012-01-01	1.001819968223570
2013-01-01	0.999199986457825
2014-01-01	0.975210011005402
2015-01-01	0.968529999256134
2016-01-01	0.962220013141632