Rutheni is only the written name for the tribe that lived in Caesar's time (and probably earlier) on the Gaul territory. We can only suppose the way their name was really pronounced, but this assumption can be quite reliable if we take into account one basic and often neglected fact that writing was and still is only an instrument (like today's tape recorders) for voice recording, of both outer sounds that could be heard, or inner ones - that are our thoughts. The difference is that tape recorders record outer voices more accurately, while the recordings on the paper of what was heard, reflexively introduce the two errors that are the consequence of the two approximations.
Slovakia (100,000) - Romania (?) - Ukraine (?) - Total (100,000)