Year	Ratio
1972-01-01	0.412490010261536
1973-01-01	0.396120011806488
1974-01-01	0.490700006484985
1975-01-01	0.473969995975494
1976-01-01	0.522740006446838
1977-01-01	0.543309986591339
1978-01-01	0.520969986915588
1979-01-01	0.595709979534149
1980-01-01	0.524860024452209
1981-01-01	0.513639986515045
1982-01-01	0.476249992847443
1983-01-01	0.528119981288910
1984-01-01	0.492830008268356
1985-01-01	0.821150004863739
1987-01-01	0.864319980144501
1991-01-01	0.729619979858398
1993-01-01	0.799459993839264
1994-01-01	0.731180012226105
1995-01-01	0.910040020942688
1996-01-01	0.906740009784698
1998-01-01	0.923690021038055
1999-01-01	0.941089987754822
2000-01-01	0.939949989318848
2001-01-01	0.928650021553040
2002-01-01	1.001629948616030
2003-01-01	1.004179954528810
2004-01-01	0.892549991607666
2005-01-01	0.888939976692200
2006-01-01	0.818840026855469
2014-01-01	1.246880054473880
2015-01-01	1.366050004959110
2016-01-01	1.433750033378600
2017-01-01	1.399620056152340