[Police] Recordings in the past

Hello all, In the past, how long has it taken for quality recordings of shows to surface? I don't usually collect bootlegs of past Police or Sting shows, so I don't know how it works. What I'm getting at is this: I've noticed a handful of shows on dime-a-dozen, but is it better to wait until after the tour is over? Is that when soundboard recordings usually surface? Yes, yes, you all know I just want to get my hands on the Chicago show, but knowing if it might ever surface would be a great first step. David[Man in a Suitacse]