Year	Ratio
1971-01-01	1.23002994060516
1972-01-01	1.24686002731323
1973-01-01	1.32523000240326
1974-01-01	1.24199998378754
1975-01-01	1.29150998592377
1976-01-01	1.23711001873016
1977-01-01	1.09801995754242
1978-01-01	1.12993001937866
1979-01-01	1.11677002906799
1986-01-01	1.23264002799988
1987-01-01	1.25988996028900
1988-01-01	1.30160999298096
1989-01-01	1.24705994129181
1990-01-01	1.27881002426147
1991-01-01	1.18497002124786
1992-01-01	1.19618999958038
1993-01-01	1.19465994834900
2001-01-01	1.17487001419067
2002-01-01	1.40060997009277
2005-01-01	1.33115994930267
2006-01-01	1.35808002948761
2007-01-01	1.36720001697540
2008-01-01	1.30724000930786
2009-01-01	1.24825000762939
2010-01-01	1.28396999835968
2011-01-01	1.35297000408173
2012-01-01	1.35304999351501
2013-01-01	1.34832000732422
2014-01-01	1.37203001976013
2015-01-01	1.31708002090454