Year Dollars 1992-01-01 512702 1997-01-01 2135859 2002-01-01 3765440 2003-01-01 4254954 2004-01-01 2730385 2005-01-01 8246504 2006-01-01 12476200 2007-01-01 4098094 2008-01-01 14911509 2009-01-01 6326056 2010-01-01 8941615 2011-01-01 12804809 2012-01-01 14237327 2013-01-01 21850207 2014-01-01 22509306 2015-01-01 19266879 2016-01-01 16660965