Absence of evidence is not evidence of absence.
There could be many reasons that such a lists don't exist or are hard to come by, beginning with the common sense observation that records are not as complete in second and third world countries and that a great many more deaths go uninvestigated or are incompetently investigated in such places.
Non-UK Europe is not a third world country. We need 279 serial killers over the past few decades to match the UK's rate. They didn't have a problem identifying them in the 17th century. What happened since then?
PS. Japan is hardly a third world nation either. Where is their list of 50?