Year	Ratio
1970-01-01	0.886789977550507
1980-01-01	1.018890023231510
1982-01-01	1.133509993553160
1983-01-01	1.081730008125310
1984-01-01	1.165169954299930
1991-01-01	1.225749969482420
2006-01-01	1.244920015335080
2007-01-01	1.258499979972840
2008-01-01	1.274770021438600
2010-01-01	1.229009985923770
2011-01-01	1.218719959259030
2012-01-01	1.214740037918090
2013-01-01	1.210970044136050
2014-01-01	1.171820044517520
2015-01-01	1.193420052528380
2016-01-01	1.163820028305050