Year Dollars 1992-01-01 1612038 1997-01-01 1323662 2002-01-01 3275671 2003-01-01 4243773 2004-01-01 5290394 2005-01-01 8737532 2006-01-01 9142548 2007-01-01 8550212 2008-01-01 7984042 2009-01-01 9747470 2010-01-01 13859854 2011-01-01 17640655 2012-01-01 16033857 2013-01-01 18849077 2014-01-01 17563277 2015-01-01 17636415 2016-01-01 19669885