My understanding is the statistic includes police shootings, in Britain they disarmed the police in large part.
The UK police have overwhelmingly never been armed.
Simply no need for all armed force, esp historically, given the low UK rates of violent crime and murder. And murder of a police officer was almost non existant, even today it makes national news.
Even today, despite the myth coming from US hype, the UK rates are still low. See my post on that in this thread.