Year Dollars 1997-01-01 21225 2004-01-01 164874 2006-01-01 49691 2007-01-01 60139 2008-01-01 65687 2009-01-01 18221 2010-01-01 22652 2011-01-01 57724 2012-01-01 36305 2013-01-01 49476 2015-01-01 26998