Note: Australia is generally considered to be a continental landmass, rather than an island. If however one does count Australia among the islands it, not Greenland, would be the largest in the world (unless one also considered Antarctica an island).
... the town the population is spread out with 22.3% under the age of 18, 6.3% from 18 to 24, 31.0% from 25 to 44, 26.9% from 45 to 64, and 13.5% who are 65 years of age ...