Funding for this research was provided by:
Received: 27 February 2019
Accepted: 17 June 2019
First Online: 29 July 2019
Ethics approval and consent to participate
: All participants provided verbal informed consent which was documented by the interviewers. This procedure is compliant with the privacy agreement: ExternalRef removedEthics approval was not required because only anonymized data were processed for this paper. The ethical permission was granted by the Scientific Advisory Board of DIW Berlin. For further questions, please contact ExternalRef removed
: Not applicable.
: The author declares that she has no competing interests.