Year	Ratio
1974-01-01	0.481720000505447
1975-01-01	0.508949995040894
1976-01-01	0.475719988346100
1977-01-01	0.571020007133484
1978-01-01	0.575280010700226
1980-01-01	0.594940006732941
1988-01-01	0.617309987545013
1989-01-01	0.636560022830963
1990-01-01	0.745750010013580
1991-01-01	0.781340003013611
1992-01-01	0.745880007743835
1993-01-01	0.796019971370697
1994-01-01	0.774429976940155
1999-01-01	1.265820026397710
2000-01-01	1.288079977035520
2003-01-01	1.435189962387080
2004-01-01	1.436830043792720
2008-01-01	1.533300042152400
2010-01-01	1.154360055923460
2012-01-01	1.375219941139220
2013-01-01	1.376489996910100
2014-01-01	1.365069985389710
2015-01-01	1.366500020027160