The data is based on the monthly data retrieved by Crossref via API. This contains information on the individual Crossref members and the number of ORCID entries they have in relation to the current data (current files) and the backfiles (in each case as a percentage). The country allocation is based on the Crossref data on the members. The data have been available since April 2016, at irregular intervals until the end of 2019 and monthly since January 2020.