Year Dollars 1992-01-01 3014794 1997-01-01 6691561 2002-01-01 10608553 2003-01-01 8767520 2004-01-01 10502814 2005-01-01 20711334 2006-01-01 31872938 2007-01-01 38802911 2008-01-01 58864799 2009-01-01 36564497 2010-01-01 42676447 2011-01-01 51917164