Year	Ratio
1970-01-01	0.487199991941452
1971-01-01	0.482560008764267
1972-01-01	0.546130001544952
1973-01-01	0.544679999351501
1974-01-01	0.507019996643066
1975-01-01	0.528519988059998
1976-01-01	0.535709977149963
1977-01-01	0.603479981422424
1978-01-01	0.607219994068146
1979-01-01	0.611479997634888
1980-01-01	0.614709973335266
1981-01-01	0.708249986171722
1982-01-01	0.720179975032806
1983-01-01	0.614260017871857
1984-01-01	0.702509999275208
1985-01-01	0.693040013313293
1986-01-01	0.688899993896484
1987-01-01	0.688069999217987
1988-01-01	0.801159977912903
1989-01-01	0.808570027351379
1990-01-01	0.842819988727570
2005-01-01	1.046489953994750
2006-01-01	1.056859970092770
2007-01-01	1.073230028152470
2008-01-01	1.062680006027220
2009-01-01	1.048509955406190
2010-01-01	1.063050031661990
2011-01-01	1.059120059013370
2013-01-01	1.044360041618350
2015-01-01	1.079669952392580
2016-01-01	1.060160040855410