Year	Ratio
1970-01-01	0.921720027923584
1971-01-01	0.893190026283264
1972-01-01	0.919290006160736
1973-01-01	0.951330006122589
1974-01-01	1.021100044250490
1975-01-01	1.047520041465760
1977-01-01	0.954349994659424
1979-01-01	1.167999982833860
1980-01-01	1.168290019035340
1982-01-01	1.193109989166260
1983-01-01	1.228719949722290
1984-01-01	1.416079998016360
1985-01-01	2.094419956207280
1986-01-01	1.836220026016240
1987-01-01	1.747670054435730
1988-01-01	1.754989981651310
1989-01-01	1.641270041465760
1998-01-01	1.199689984321590
1999-01-01	1.206439971923830
2000-01-01	1.194229960441590
2001-01-01	1.197810053825380
2002-01-01	1.189890027046200
2004-01-01	1.162520051002500
2005-01-01	1.163290023803710
2006-01-01	1.160179972648620
2007-01-01	1.155719995498660
2008-01-01	1.161350011825560
2010-01-01	1.128129959106450