Year	Percent
2005-01-01	6.11208372501163
2006-01-01	5.96271256968683
2007-01-01	6.06387880934694
2008-01-01	6.09257811139739
2009-01-01	6.38122188894565
2010-01-01	7.50938379041158
2011-01-01	7.10020687108927
2012-01-01	7.49055053267648
2013-01-01	7.67081140285129
2014-01-01	8.28538060825225
2015-01-01	8.22176077211030
2016-01-01	8.57333160985511
2017-01-01	8.73098990363764