Funding for this research was provided by:
Bundesministerium für Bildung und Forschung (03F0775A, 03F0788A)
BONUS MICROPOLL project supported by BONUS (Art 185), funded jointly by the European Union
Received: 5 December 2018
Accepted: 15 September 2019
First Online: 23 October 2019
Change Date: 6 December 2019
Change Type: Correction
Change Details: An amendment to this paper has been published and can be accessed via a link at the top of the paper.
: The authors declare no competing interests.