Scurvy is rare compared to other nutritional deficiencies. It occurs more often in the developing world in association with malnutrition. Rates among refugees are reported at 5 to 45 percent. Scurvy was described as early as the time of ancient Egypt. It was a limiting factor in long-distance sea travel, often killing large numbers of people. During the Age of Sail, it was assumed that 50 percent of the sailors would die of scurvy on a major trip. A Scottish surgeon in the Royal Navy, James Lind, is generally credited with proving that scurvy can be successfully treated with citrus fruit in 1753. Nevertheless, it wouldn't be until 1795 before health reformers such as Gilbert Blane persuaded the Royal Navy to routinely give lemon juice to its sailors.