Year	Ratio
2000-01-01	54.5458440690451
2001-01-01	55.8966911964632
2002-01-01	59.6543939182018
2003-01-01	64.7666885460271
2004-01-01	70.9488074323602
2005-01-01	78.2902304854954
2006-01-01	85.6144861685947
2007-01-01	86.4974042544136
2008-01-01	86.0378048157734
2009-01-01	87.8272603087576
2010-01-01	88.3000000000000
2011-01-01	86.7000000000000
2012-01-01	85.5000000000000
2013-01-01	82.1000000000000
2014-01-01	77.9000000000000
2015-01-01	72.7000000000000
2016-01-01	69.4000000000000
2017-01-01	66.4000000000000