Well, that's the problem with getting averages though. London is relatively fine, there are issues but very broadly speaking there is enough officers there. The problems start outside - in Manchester/Leeds/Doncaster the numbers are so low that what I mentioned above happens daily. If it's "just" theft or burglary and no one is hurt forget about any investigation. Even if you have CCTV of it happening, the police just don't want it as no one would review it anyway.
Greater Manchester has a population of 2.8M, and a police force of 6237, meaning the number of police is 223 per 100000, which is higher than the UK average.
I think the real problem here is that the citizens of Japan police themselves, and the citizens of most western countries like the UK don't.
