Year Dollars 1997-01-01 56933 2002-01-01 131417 2007-01-01 525419 2009-01-01 1867967 2010-01-01 1506117 2011-01-01 614447 2012-01-01 935107 2013-01-01 2537278 2014-01-01 3317352 2016-01-01 342972