A group of volcanic South Pacific islands, Pitcairn is Britain's most isolated dependency. Pitcairn Island was the last refuge for the mutineers from HMS Bounty. The economy operates by barter, fishing, and subsistence farming, and is reliant on regular airdrops from New Zealand and periodic visits by supply vessels. Postage stamp sales provide foreign currency earnings. In 2002 20 Pitcairners were charged with sexual assault.