Year	Ratio
1971-01-01	1.32076001167297
1973-01-01	1.28515994548798
1979-01-01	1.17818999290466
1980-01-01	1.17835998535156
1981-01-01	1.19811999797821
1982-01-01	1.20139002799988
1992-01-01	1.49125003814697
1995-01-01	1.37426996231079
1996-01-01	1.36087000370026
1998-01-01	1.32583999633789
1999-01-01	1.26628005504608
2001-01-01	1.10061001777649
2002-01-01	1.29878997802734
2003-01-01	1.28236997127533
2004-01-01	1.27775001525879
2005-01-01	1.22976005077362
2006-01-01	1.24611997604370
2008-01-01	1.24207997322083
2009-01-01	1.23424994945526
2010-01-01	1.24905002117157
2011-01-01	1.23696005344391
2012-01-01	1.22705996036530
2013-01-01	1.25986003875732
2014-01-01	1.28064000606537
2017-01-01	1.32074999809265