Year	Ratio
1971-01-01	0.733650028705597
1972-01-01	0.835650026798248
1977-01-01	0.857540011405945
1988-01-01	0.923330008983612
2003-01-01	1.163490056991580
2004-01-01	1.032789945602420
2005-01-01	1.059910058975220
2007-01-01	1.065179944038390
2008-01-01	1.062459945678710
2009-01-01	1.111590027809140
2010-01-01	1.018169999122620
2011-01-01	1.142349958419800
2012-01-01	1.127609968185420
2013-01-01	1.102489948272710
2014-01-01	1.095589995384220
2015-01-01	1.106690049171450
2016-01-01	1.134130001068120
2017-01-01	1.149999976158140