Year	Ratio
1996-01-01	33.1628139106465
1997-01-01	33.3951715256911
1998-01-01	32.8319305050995
1999-01-01	33.8175834145958
2000-01-01	33.9373348520132
2001-01-01	34.3389422124345
2002-01-01	35.3037187611348
2003-01-01	36.8325280648921
2004-01-01	38.7977473411008
2005-01-01	41.5847124608427
2006-01-01	44.0003163040975
2007-01-01	46.3495589797650
2008-01-01	48.3656064327221
2009-01-01	52.3297329368887
2010-01-01	53.5645941822100
2011-01-01	54.5645279350652
2012-01-01	54.9258380018618
2013-01-01	55.3018996470769
2014-01-01	55.3840404091111
2015-01-01	55.9021356522182
2016-01-01	57.0462439218021
2017-01-01	58.3826578781542