Year	Ratio
1979-01-01	1.139350056648250
1980-01-01	0.913250029087067
1981-01-01	1.059209942817690
2006-01-01	2.231260061264040
2007-01-01	2.501669883728030
2008-01-01	2.093569993972780
2009-01-01	2.568890094757080
2010-01-01	2.106760025024410
2011-01-01	2.118429899215700
2012-01-01	2.028280019760130
2013-01-01	2.257289886474610
2014-01-01	1.891909956932070
2015-01-01	2.318130016326900
2017-01-01	1.675320029258730