Eurostat (European Statistical Office; DG ESTAT) is a Directorate-General of the European Commission (…). Eurostat’s main responsibilities are to provide statistical information to the institutions of the European Union (EU) and to promote the harmonisation of statistical methods across its member states and candidates for accession as well as EFTA countries.
The UK not being included makes me think that these are only EU member countries? I don’t know for sure though.
Switzerland is included though. I’m thinking it’s just data availability.
It literally says Eurostat in the bottom right