Year	Ratio
1971-01-01	0.257050007581711
1972-01-01	0.282029986381531
1977-01-01	0.370779991149902
1978-01-01	0.402009993791580
1980-01-01	0.467310011386871
1981-01-01	0.486059993505478
1982-01-01	0.512290000915527
1983-01-01	0.542789995670319
1984-01-01	0.551490008831024
1993-01-01	0.821560025215149
1994-01-01	0.852869987487793
1995-01-01	0.876590013504028
1996-01-01	0.903389990329742
1997-01-01	0.916270017623901
1998-01-01	0.930280029773712
1999-01-01	0.941330015659332
2000-01-01	0.959869980812073
2001-01-01	0.975639998912811
2002-01-01	0.990480005741119
2003-01-01	1.006360054016110
2004-01-01	1.022119998931880
2005-01-01	1.036890029907230
2006-01-01	1.039559960365300
2007-01-01	1.042729973793030
2008-01-01	1.043670058250430
2009-01-01	1.043519973754880
2010-01-01	1.035509943962100
2011-01-01	1.025900006294250
2012-01-01	1.016950011253360
2013-01-01	1.006809949874880
2014-01-01	1.006319999694820
2015-01-01	1.002189993858340
2016-01-01	1.021860003471370