Year	Ratio
1971-01-01	1.446869969367980
1972-01-01	1.531129956245420
1973-01-01	1.870990037918090
1974-01-01	1.446939945220950
1975-01-01	1.390820026397710
1976-01-01	1.550549983978270
1977-01-01	1.555349946022030
1978-01-01	1.041589975357060
1979-01-01	0.843100011348724
1980-01-01	1.004570007324220
1981-01-01	0.918900012969971
1982-01-01	1.059749960899350
1985-01-01	1.388180017471310
1986-01-01	1.598899960517880
1987-01-01	1.321609973907470
1988-01-01	1.600059986114500
1991-01-01	1.381989955902100
1992-01-01	1.588039994239810
1993-01-01	1.530529975891110
1994-01-01	1.578029990196230
1995-01-01	1.616729974746700
1996-01-01	1.677010059356690
1999-01-01	1.775140047073360
2003-01-01	2.188560009002690
2005-01-01	3.064179897308350
2006-01-01	3.152060031890870
2011-01-01	1.711279988288880
2012-01-01	2.034140110015870
2013-01-01	2.242029905319210
2014-01-01	1.983690023422240
2015-01-01	1.920570015907290
2016-01-01	1.868039965629580