Year	Ratio
1975-01-01	0.979480028152466
1976-01-01	0.943189978599548
1978-01-01	0.970430016517639
1979-01-01	0.978330016136169
1980-01-01	0.950820028781891
1981-01-01	0.953199982643127
1982-01-01	0.971360027790070
1983-01-01	0.982879996299744
1984-01-01	0.965510010719299
1985-01-01	0.970430016517639
1986-01-01	0.988870024681091
1987-01-01	0.991089999675751
1991-01-01	0.993560016155243
1992-01-01	1.006389975547790
1993-01-01	1.013700008392330
1994-01-01	1.035760045051570
1995-01-01	1.026039958000180
1996-01-01	1.014099955558780
1997-01-01	1.028460025787350
1998-01-01	1.021209955215450
1999-01-01	1.012609958648680
2000-01-01	1.013620018959050
2001-01-01	1.012979984283450
2002-01-01	1.013290047645570
2003-01-01	1.002449989318850
2004-01-01	0.994799971580505
2005-01-01	0.999840021133423
2006-01-01	0.998600006103516
2007-01-01	0.993860006332397
2008-01-01	0.986270010471344
2009-01-01	0.983150005340576
2010-01-01	0.977190017700195
2011-01-01	0.976040005683899
2012-01-01	0.971949994564056
2013-01-01	0.971819996833801
2014-01-01	0.979900002479553
2015-01-01	0.981869995594025
2016-01-01	0.977429986000061