Plymouth Colony lost close to eight percent of its adult male population and a smaller percentage of women and children to Indian warfare or other causes associated with the war.:332 Indian losses were much greater, with about 2,000 men killed or who died of injuries in the war, more than 3,000 dying of sickness or starvation, and another 1,000 Indians sold into slavery and transported to other areas, such as the British-controlled islands in the Caribbean. About 2,000 Indians escaped to other tribes to the north or west; they joined continued Indian attacks from those bases well into the next century. Historians estimate that, as a result of King Philip's War, the Indian population of southern New England was reduced by about 40 to 80 percent. The war escalated from a local conflict to involve most of southern New England and reached to other east coast areas as well. The war killed nearly as high a percentage of the Indian population as the plagues of 1616-19. It is estimated that the Indians of New England made up almost 30 percent of the total regional population, but the Indian population had dropped to less than 15 percent by 1680, five years after the war began.:345 The settlers incurred an enormous tax burden to pay for the war, which held back the economy of the entire region for many years.:346
Question: How many percent did the Indian population drop five years after the war began?
Answer: 15