Mathematically, no, it doesn't mean that. For a start, cases being cleared doesn't even imply that someone was arrested, just that the police decided they knew

Mathematically, no, it doesn't mean that. For a start, cases being cleared doesn't even imply that someone was arrested, just that the police decided they knew who did it. There could be zero false imprisonments and also close to zero accurate convictions, if the prosecutors just picked someone with a slam dunk case for one murder and accused them of all the others as well. Even easier if they pick a dead guy and close the case with him the assumed perpetrator - as referenced in the second paragraph of that article - because there's less chance that someone will fight the accusation. But either way, all the murderers except the one fall guy were able to walk away, and the police got a 100% clearance rate.