Year Dollars 1992-01-01 35831612 1997-01-01 353524184 2006-01-01 482187828 2008-01-01 472681896 2009-01-01 536655258 2012-01-01 265426872 2013-01-01 391090721 2014-01-01 294703660 2015-01-01 251681114 2016-01-01 227689394