Funding for this research was provided by:
Norges Forskningsråd (256644)
Myndigheten för Samhällsskydd och Beredskap (2013-4176)
Text and Data Mining valid from 2018-12-01
Received: 3 July 2018
Accepted: 3 December 2018
First Online: 13 December 2018
Ethics approval and consent to participate
: We use aggregate non-sensitive data. The data set is aggregated from individual data and the consent to participate was waived under the following ethics approval: Ethics approval was granted by the Regional Ethics Committee South-East, Norway (ref. 2013/796b) and the Norwegian Data Inspectorate (ref. 13/00993).
: Not applicable.
: The authors declare that they have no competing interests.The funding bodies have no role in the development of this research.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.