Year	Ratio
1971-01-01	0.847419977188110
1973-01-01	0.863870024681091
1975-01-01	0.876749992370605
1977-01-01	0.892300009727478
1978-01-01	0.914080023765564
1979-01-01	0.921389997005463
1980-01-01	0.945439994335175
1981-01-01	1.096940040588380
1982-01-01	0.894289970397949
1983-01-01	0.906210005283356
1984-01-01	0.934409976005554
1986-01-01	0.935699999332428
1987-01-01	0.907100021839142
1988-01-01	0.936219990253448
1989-01-01	0.945829987525940
1990-01-01	0.975619971752167
1991-01-01	1.008409976959230
1993-01-01	1.093520045280460
1998-01-01	1.348199963569640
1999-01-01	1.439650058746340
2000-01-01	1.427230000495910
2001-01-01	1.396239995956420
2002-01-01	1.376839995384220
2003-01-01	1.322669982910160
2004-01-01	1.322810053825380
2005-01-01	1.325350046157840
2006-01-01	1.271229982376100
2007-01-01	1.306579947471620
2008-01-01	1.292520046234130
2009-01-01	1.297199964523320
2011-01-01	1.321580052375790
2012-01-01	1.319090008735660
2013-01-01	1.345849990844730
2014-01-01	1.344079971313480
2015-01-01	1.382990002632140
2016-01-01	1.399320006370540