1.5 Billion £1 coins in circulation. Moreover, Hedge Fund returns are so poor because of the sudden rise of competition.

Guess - Number of all the pound notes printed * 3 because minimum pound note value is 5 and when you ask for change, you would need at least [5 1-pound coins] or [2 pound coin + 3 1-pound coins.] I think the UK mint wouldn't have it made X5 because there is still the 2 pound coin to exchange so X3.