Targets of the Yankee whalers from the east coast of the US during the 18th and 19th centuries, sperm whales were killed primarily for their spermaceti oil. Modern hunts, from 1945 to 1984, also focused on sperm whales, particularly in the Pacific. Although the sperm whales are considered protected by the IWC a few sperm whales are taken under the auspices of a "scientific" whaling program in Japan. Prior to the hunts, sperm whales numbered in the millions, but the most recent estimate puts the global population of sperm whales at around 360 000 animals.