It's possibly related to when you create a hunter, those coins are locked and no longer spendable ever again. when a player is refunded or killed, those coins are then generated/minted and put back into the coin supply. It's probably totalling up everything including the locked/destroyed coins.

The total supply is approx = ((block height * 10)+85000) - (amount of coins not generated when the Crown of fortune was not held)

There is also a lot of coins from the cost of destructs which was to be used for things like NPCs etc in some future update.

IF you use the old client (not the one based on bitcoin core, the ancient one), domob implemented an rpc that counts and verifies the number of coins (what there should be vs what there is).