what are the administrative areas for saint helena, ascension, and tristan da cunha?
saint helena, ascension island, tristan da cunha, tristan da cunha, inaccessible island, nightingale island, gough island
which administrative centers have a population above 0?
saint helena, ascension island, tristan da cunha, tristan da cunha, gough island
out of those centers, which has the lowest population?
gough island