from 600 to 1,600 grams of eiderdown fill; a simple 800 gram duvet sells for about 640,000 Icelandic króna (US$5,116) as of 2021. In Iceland and Scandinavia, colonies of more than 5,000 birds sometimes develop in "farmed" areas, while in some protected areas of the Novaya Zemlya archipelago, nest densities exceed 13,000 per hectare (more than 5,260 per acre). On the other hand, the more nomadic indigenous peoples of Arctic Canada did not see down production as a reasonable source of income and tended to overexploit eider nests with "indifferent" collection of down feathers from the nests. Although the down feathers of various species of wildfowl, gulls and other seabirds have historically been used for insulation, most now come from domestic geese. Some 70 percent of the world's supply comes from China, typically from birds killed for their meat. Most of the rest comes from Europe and Canada, from birds harvested for meat or pâté. A portion of the world's supply of down feathers are plucked from live birds, a practice condemned as cruel by animal welfare groups. The precise percentage of down harvested in this manner is uncertain; while some references report that it is only a small fraction of the total (less than 1% in 2011), a 2009 Swedish documentary reported that it might be as much as 50–80% of the total supply, a figure supported by IKEA and an industry representative, but disputed by organizations within the industry. The documentary also shows birds lying on the floor with large flesh wounds from the plucking, after which the wounds were stitched using a needle and thread without anesthetic. Although live-plucking is illegal in Canada, the United States and Europe, it is known to occur in two European countries (Poland and Hungary) and in China. Public sentiment against the practice has, in some countries, been strong. IKEA and clothing manufacturer Patagonia have altered product lines to eliminate the use (or possible use) of live-plucked down. In the United States, Federal Trade Commission regulations require that any product labeled "100% Down" must contain only down feathers, while products labeled simply "Down" can contain a mixture of fiber and feathers. In addition, products labeled as "Goose Down" must contain at least 90% goose down, 10% goose feathers. Down insulation is rated by fill power, which is the number of cubic inches displaced by a given ounce of down (in3/oz). To measure