They consist of atolls and volcanic islands from less than 3 metres above sea level to almost 5,000 metres above sea level and total land areas between, the smallest Nauru, 21 km2 and, the largest PNG, 462,840 km2. The populations of these countries range from 10,800 (Nauru) to more than 8 million people (PNG) for a total of some 10 million people, with densities as low as 18 people per km2 in PNG to as high as 514 people per km2 in Nauru. Official development assistance (ODA) in 2014 ranged from US$22 million in Nauru to a high of US$681 million in PNG.