In an attempt to try answering a vague question I would think the question is basically how many slabbed coins are left compared to how many have been made. That would include the ones reslabbed more than once. Based on a limited amount of exposure to the entire world of collectors in my one small area of this planet I would think only about 25% of all the slabbed coins are still in slabs. I base that only on the fact I do not know anyone that saves slabbed coins, keeps slabbed coins, wants slabbed coins. Out of all the coin shows I go to I see predominately raw coins and many dealers also tell me they don't really like slabbed coins or at least the excessively common ones. They only send in coins to verify the authenticity ofthe coin in instances where it is a valuable coin. Way, way to many people send in just about anything to a TPG service. I've seen coins worth only a dollar or two in slabs. Not even worth the time to break open the slab.
There's a pretty good reason that most of the coins you see anywhere are raw - 80% to 85% of them can't be slabbed to begin with.