Funding for this research was provided by:
Norges Forskningsråd (SAMRISK2014)
Text and Data Mining valid from 2018-05-30
Received: 19 October 2017
Accepted: 8 May 2018
First Online: 30 May 2018
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.