Notes: Geometric mean is not reported in the BETSI survey by The Swedish National Board of Housing, Building and Planning. The Swedish National Board of Housing, Building and Planning conducted a radon survey in 2007-2008. The survey, which included both apartments in residential buildings as well as single households in detached houses, was part of the so called BETSI-project and the main report of this project was published 2009. The reported average is not population based but serves as an estimation for all dwellings.   