Year Number 2007-01-01 0.0222 2008-01-01 0.0662 2009-01-01 0.0659 2010-01-01 0.0219 2011-01-01 0.0437 2012-01-01 0.0436 2013-01-01 0.0436 2014-01-01 0.0435 2015-01-01 0.0435 2016-01-01 0.0435 2017-01-01 0.0435