Received: 28 November 2020
Accepted: 20 August 2021
First Online: 7 September 2021
: This study is approved by the ethical board of the University of Tokyo in JAPAN in July 2016 (the ethical approval number 11763). The self-reporting questionnaire provided an explanation of the survey and its privacy as well as a request for consent to participate in the survey. Informed consent was obtained from all study participants included in this study. All methods were performed in accordance with the relevant guidelines and regulations.
: Not applicable.
: The authors declare that they have no competing interests.