Year	Ratio
1981-01-01	1.193379998207090
1982-01-01	1.099089980125430
1983-01-01	1.098719954490660
1984-01-01	1.073740005493160
1985-01-01	1.073570013046260
1986-01-01	1.048220038414000
1987-01-01	1.039790034294130
1988-01-01	0.993600010871887
1989-01-01	0.993120014667511
1990-01-01	1.038050055503850
1998-01-01	1.098709940910340
1999-01-01	1.098080039024350
2001-01-01	1.101459980010990
2002-01-01	1.106699943542480
2003-01-01	1.107759952545170
2004-01-01	1.111240029335020
2005-01-01	1.119109988212590
2006-01-01	1.117239952087400
2007-01-01	1.102509975433350
2008-01-01	1.090019941329960
2009-01-01	1.081230044364930
2013-01-01	1.089509963989260
2015-01-01	1.085919976234440