Year Number 2004-01-01 0.0000 2005-01-01 0.0000 2006-01-01 0.0000 2007-01-01 0.0000 2008-01-01 2.3307 2009-01-01 7.1520 2010-01-01 7.5290 2011-01-01 7.9543 2012-01-01 8.3904