The numbers of carjackings in the District is going down after a yearslong surge, according to U.S. Attorney for D.C. Matthew Graves. U.S. Attorney for D.C. Matthew Graves announces carjackings have decreased in the District since last year. (WTOP/Shayna Estulin) U.S. Attorney for D.C. Matthew Graves announces carjackings have decreased in the District since last…