Text and Data Mining valid from 2018-09-26
Received: 8 May 2018
Accepted: 16 September 2018
First Online: 26 September 2018
Ethics approval and consent to participate
: We used publicly available, aggregate country-level data from existing data sources; therefore, this analysis was not considered human subjects research and did not require ethical review. Participatory consent was not applicable.
: Not applicable.
: The authors declare that they have no competing interests.
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