The number of passengers at Rhode Island’s T.F. Green Airport has risen, with new figures showing a jump of more than 7 percent in May compared with a year ago. Statistics released by the Rhode Island Airport Corp. show that 340,649 passengers traveled through the state’s main airport in Warwick last month. That was up from 317,482 in the same period a year earlier. The number of passengers at T.F. Green has been on a steady decline overall. The airport saw a 6 percent drop last year compared with 2011. People who make round trips are counted twice in the statistics.