This nice visualization seems to be based on numbers from Comparitech's 'The World's Most Surveilled Cities' (which is worth a read). Which states China's numbers can only be based on estimates (as the CCP doesn't publicly disclose any real numbers): the speculative nature of which, possibly being the reason why it's not included here. The others are based on sources (one has to request access to, for some reason: which I'm not willing to do), but doubt represent reality: as it correctly recognizes many "private" cameras are public facing (especially in the Western world), which also makes it near impossible to discern which are actually public facing (which might not be all that relevant).

Any data processor of relevant size within the European Union (including those processing camera footage), is required by the GDPR to have an effective government agent (or "data protection officer") to oversee their operation. This agent (likely "working" for multiple processors) under professional secrecy, is legally required to comply with authorities' requests for additional processing (including: making accessible such data, apply processing operations outside of its processor's legal basis (without disclosing it to them), or even delete information): requests not to be disclosed publicly. So effectively, the EU's authorities have a legal backdoor to all these "private" cameras; and if visualized would create an entirely different picture.