It would be very unexpected to see that more than 100 billion XRP existed prior to #32570. With current transaction types etc. it is impossible in Ripple to issue more XRP, so the amount in #32570 is the maximum we know about
Is it at all possible that a transaction type existed before #32570 that could have allowed more XRP to be created, and then that transaction type was removed prior to ledger #32570 being published?