Funding for this research was provided by:
Swedish National Space Agency (193-17)
Text and Data Mining valid from 2019-12-01
Received: 15 September 2019
Accepted: 5 December 2019
First Online: 23 December 2019
Ethics approval and consent to participate
: The Regional Ethical Review Board in Umeå approved the study (Approval number: 2012-396-32M), which was conducted in accordance with the Declaration of Helsinki, and all participants gave their informed, written consent.
: Not applicable.
: The authors declare that they have no competing interests.