Year	Ratio
2008-01-01	83.8772366418981
2009-01-01	85.9087614379305
2010-01-01	84.9803728406436
2011-01-01	82.9886467181569
2012-01-01	84.0094989876385
2013-01-01	85.3212161863615
2014-01-01	87.2014331907146
2015-01-01	89.8937405119657
2016-01-01	95.6199102881801