Document is current

Article History

Received: 11 July 2018

Accepted: 20 February 2019

First Online: 6 March 2019

Ethics approval and consent to participate

: Not required.

: Not applicable.

: All authors have completed the ICMJE uniform disclosure form at ExternalRef removed (available on request from the corresponding author) and declare that (1) no authors have support from any company for the submitted work; (2) IB is the deputy director of French EQUATOR that might have an interest in the work submitted; (3) no author’s spouse, partner, or children have any financial relationships that could be relevant to the submitted work; and (4) none of the authors has any non-financial interests that could be relevant to the submitted work.

: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.