Year	Ratio
1970-01-01	0.768029987812042
1971-01-01	0.837570011615753
1972-01-01	0.873549997806549
1973-01-01	0.854560017585754
1974-01-01	0.844990015029907
1975-01-01	0.929910004138947
1976-01-01	0.931770026683807
1977-01-01	0.924040019512177
1978-01-01	1.008790016174320
1979-01-01	0.987529993057251
1980-01-01	1.015050053596500
1981-01-01	1.138949990272520
1982-01-01	1.133730053901670
1983-01-01	1.162979960441590
1984-01-01	1.145040035247800
1985-01-01	1.114719986915590
1986-01-01	1.139760017395020
1987-01-01	1.156980037689210
1999-01-01	1.630220055580140
2000-01-01	1.546740055084230
2001-01-01	1.480049967765810
2002-01-01	1.489480018615720
2003-01-01	1.513679981231690
2004-01-01	1.424000024795530
2005-01-01	1.456329941749570
2006-01-01	1.521520018577580
2007-01-01	1.519940018653870
2008-01-01	1.521669983863830
2009-01-01	1.509389996528630
2010-01-01	1.507650017738340
2011-01-01	1.561969995498660
2012-01-01	1.572950005531310
2013-01-01	1.608809947967530
2014-01-01	1.619470000267030
2015-01-01	1.636150002479550