The Agriculture of the Tongan Archipelago is largely based on the farming of yams, squash, and root crops. Agriculture consists of 16–29.9% of Tonga's GDP, 34% of its labour force, and about 50% of its exports. Since the 1980s, Tonga's agricultural exports expanded to include vanilla, watermelons, sugar, and legumes. With the expansion of the archipelago's population, climate change, and competitive markets, Tonga has trouble keeping up with competitive demand.