Year	Ratio
1971-01-01	0.0785600021481514
1972-01-01	0.0871599987149239
1974-01-01	0.1172600015997890
1985-01-01	0.1801899969577790
1987-01-01	0.1881600022315980
1989-01-01	0.1976400017738340
1990-01-01	0.2236700057983400
1994-01-01	0.2236399948596950
1995-01-01	0.2388699948787690
1996-01-01	0.2501400113105770
1997-01-01	0.2589299976825710
1998-01-01	0.2623800039291380
1999-01-01	0.2643600106239320
2000-01-01	0.2876200079917910
2001-01-01	0.3079299926757810
2002-01-01	0.3352900147438050
2003-01-01	0.3244400024414060
2004-01-01	0.3333500027656560
2005-01-01	0.3473599851131440
2006-01-01	0.3597300052642820
2007-01-01	0.4494900107383730
2008-01-01	0.4126099944114690
2009-01-01	0.4132899940013890
2010-01-01	0.4231399893760680
2011-01-01	0.4377300143241880
2012-01-01	0.4573499858379360
2013-01-01	0.4601899981498720
2014-01-01	0.4519900083541870
2015-01-01	0.4510099887847900
2016-01-01	0.4615100026130680