Year	Ratio
1973-01-01	0.343309998512268
1976-01-01	0.331620007753372
1977-01-01	0.273739993572235
1979-01-01	0.257679998874664
1980-01-01	0.323080003261566
1981-01-01	0.235689997673035
1984-01-01	0.414730012416840
1985-01-01	0.404680013656616
1986-01-01	0.471529990434647
1987-01-01	0.463310003280640
1988-01-01	0.481050014495850
1989-01-01	0.497289985418320
1990-01-01	0.509930014610291
1998-01-01	0.939760029315948
1999-01-01	0.990530014038086
2000-01-01	1.028890013694760
2001-01-01	1.081369996070860
2002-01-01	1.100170016288760
2003-01-01	1.099769949913020
2004-01-01	1.025959968566890
2005-01-01	1.065680027008060
2006-01-01	1.056660056114200
2007-01-01	1.053359985351560
2008-01-01	1.125470042228700
2009-01-01	1.078729987144470
2010-01-01	1.122969985008240
2011-01-01	1.152160048484800
2012-01-01	1.137830018997190
2013-01-01	1.082739949226380
2015-01-01	1.128870010375980
2016-01-01	1.104820013046260