Voters in the 13th congressional district went to the polls in Manhattan and the Bronx more than a week ago, but votes in the Democratic primary race for Congressman Charles Rangel’s seat were still being counted Thursday. New numbers showed Rangel’s margin growing to a lead of 945 votes over his chief rival, state Senator Adriano Espaillat. “It seems that both sides are cooperating with each other and with the board and we are making good progress,” said Board of Elections counsel Steven Richman. It could take a couple of days to count all of the more than 2,000 absentee and affidavit ballots in the race. BOE officials began opening them in Greenwich Village on Thursday morning.