Year Number 2006-01-01 7.554814109 2007-01-01 22.100075820 2008-01-01 12.329749100 2009-01-01 21.261792450 2010-01-01 24.688484180 2011-01-01 28.315256690 2012-01-01 27.984857310 2013-01-01 29.856957090 2014-01-01 23.444494180