Year Number 2006-01-01 10968.25 2007-01-01 10919.25 2008-01-01 10561.75 2009-01-01 5679.25 2010-01-01 5537.75 2011-01-01 5185.50 2012-01-01 4955.50 2013-01-01 4490.50 2014-01-01 4292.25 2015-01-01 4429.00 2016-01-01 4853.25 2017-01-01 5085.50