The Data Citation Corpus currently references to ~45,000 organizations in the affiliations and funders fields. Of these, ~13,000 have external identifiers assigned and ~10,000 of those are ROR IDs.
Ideally, we would like to match as many organizations as possible to ROR IDs as ROR is the main open persistent identifier for organizations. Many of these organizations can be matched to ROR either by name or by another ID type such as GRID, Funder Registry or ISNI.