Oslo - Urban region - Boroughs by inhabitants and area (2015)

As defined in January 2004 by the city council:

Reference 1: Inhabitants (2015) and Area in km².

Reference 2: Alna, Bjerke, Frogner, Gamle Oslo, Grorud, Grünerløkka, Nordre Aker, Nordstrand, Sagene, St. Hanshaugen, Stovner, Søndre Nordstrand, Ullern, Vestre Aker, Østensjø and Overall.

Source: http://en.wikipedia.org/wiki/Oslo