> How do you calculate this value of zero percent?

This gets messy for obvious topological/continuity reasons, but a shocking number of applications are both correct and simple to reason about if you choose to define 0/0 == 0 (kind of like how if you choose to universally define sum(empty_set) == 0 and product(empty_set) == 1 then tons of higher-level formulae just work and don't have to special-case a base case).

In context, there's no good reason to pick that definition of 0/0 per se (other than my prior that 0/0 == 0 probably simplifies some downstream math), but it's kind of nice to see that if crime is at 0% then there is also zero crime.

> And who wrote the headline?

Now we're asking the real questions ;)