Funding for this research was provided by:
Bundesministerium für Bildung und Forschung (01EL1822B)
Received: 7 January 2021
Accepted: 28 April 2021
First Online: 17 May 2021
Change Date: 29 October 2021
Change Type: Update
Change Details: The funding note was missing in the original publication. The article has been updated to rectify the error.
: For this study, ethical approval and consent to participate were not required because existing data were used and no primary data were collected.
: Not applicable.
: The authors declare that they have no competing interests.