Year Dollars 1992-01-01 7543554 1997-01-01 10245022 2002-01-01 16235705 2003-01-01 21542781 2004-01-01 18584632 2005-01-01 12362626 2006-01-01 18116705 2007-01-01 12983637 2008-01-01 15117563 2009-01-01 10770679 2010-01-01 12981338 2011-01-01 17725867 2012-01-01 14351901 2013-01-01 18278587 2014-01-01 22744464 2015-01-01 23348218 2016-01-01 24627839