Received: 5 August 2021
Accepted: 14 December 2021
First Online: 19 January 2022
: All the methods were carried out in accordance with relevant guidelines and regulations. An ethical approval by an institutional review board is not required for this study because we analyzed aggregated data that are publicly available as government statistics. Informed consent is also not needed for this study because we did not obtain the data from individual patients, and individual information are not included in the data.Not applicable.
: Not applicable.
: The authors have no conflict of interest associated with the material presented in this paper.