Nearly all bitcoins still exist. Relatively few have been destroyed. I think the total amount of destroyed bitcoins is less than 150 BTC.
What do you count as a
destroyed Bitcoin? Just one that has been sent with an unspendable script?
The Counterparty proof-of-burn address has over 2130 Bitcoins in it, and I don't think anybody is going to be able to spend those any time soon.