By solving more than half of the rapes and attempted rapes reported in Boston last year, the city’s police department is ahead of both the Northeast, with 48.5 percent, and the national average, about 44 percent, according to FBI statistics.

Boston’s clearance rate for rapes, although still better than that of other agencies, has declined every year since 2000. But department spokeswoman Beverly Ford says the nine points of difference in statistics in the past few years are insignificant.

Massachusetts’ expanding statewide DNA databank could help to further improve the numbers, as could a new policy that requires the sexual assault unit to notify all Boston police district captains when someone is sexually assaulted by a stranger and gives the captains more access to police reports so they can alert the public of possible serial rapists.

“Information is key, not only from the public, but also from units working within the department,” says Superintendent Paul Joyce, chief of the bureau of investigative services.