Year Ratio 1977-01-01 0.363240003585815 1978-01-01 0.373479992151260 1979-01-01 0.384570002555847 1980-01-01 0.405640006065369 1981-01-01 0.430700004100800 1982-01-01 0.454089999198914 1983-01-01 0.481779992580414 1984-01-01 0.495260000228882 1985-01-01 0.477109998464584 1986-01-01 0.482740014791489 1987-01-01 0.484100013971329 1988-01-01 0.476110011339188 1989-01-01 0.495460003614426 1990-01-01 0.527970016002655 1991-01-01 0.540629982948303 1992-01-01 0.551150023937225 1993-01-01 0.568790018558502 1994-01-01 0.585910022258759 1995-01-01 0.596970021724701 1996-01-01 0.606329977512360 1998-01-01 0.701200008392334 1999-01-01 0.721249997615814 2000-01-01 0.750699996948242 2001-01-01 0.754980027675629 2002-01-01 0.775229990482330 2003-01-01 0.807160019874573 2004-01-01 0.830290019512177 2005-01-01 0.866569995880127 2006-01-01 0.897520005702972 2007-01-01 0.924409985542297 2008-01-01 0.991310000419617 2009-01-01 1.007740020751950 2010-01-01 0.989730000495911 2011-01-01 0.991750001907349 2012-01-01 0.998969972133636 2013-01-01 1.012199997901920 2014-01-01 1.016510009765630 2015-01-01 1.028599977493290 2016-01-01 1.020009994506840