Year	Ratio
1981-01-01	1.36798000335693
1982-01-01	1.36549997329712
1983-01-01	1.38127005100250
1984-01-01	1.44752001762390
1985-01-01	1.46360003948212
1986-01-01	1.62056994438171
1987-01-01	1.83887004852295
1988-01-01	1.69524002075195
1989-01-01	1.72534000873566
1990-01-01	1.43384003639221
1991-01-01	1.29502999782562
1992-01-01	1.19231998920441
1997-01-01	1.51276004314423
1998-01-01	1.47047996520996
1999-01-01	1.64511001110077
2000-01-01	1.78044998645782
2001-01-01	1.66808998584747
2002-01-01	1.65179002285004
2003-01-01	1.66812002658844
2004-01-01	1.71043002605438
2005-01-01	1.78235995769501
2006-01-01	1.79560005664825
2007-01-01	1.84844994544983
2008-01-01	1.89127004146576
2009-01-01	1.83152997493744
2010-01-01	1.75953996181488
2011-01-01	1.63692998886108
2012-01-01	1.53894996643066
2013-01-01	1.50032997131348
2014-01-01	1.41650998592377
2015-01-01	1.54449999332428