Wasn't there some nonsense somewhere about how many angels could fit onto the head of a pin? Pinhead has been used as a measurement, as has match-head. And a grain, for medications. And pea-sized. So maybe we could have a word for measuring tiny things like Pension Increases or the interest on savings, a word such as a Tiddle or a Smidge. ("Pensions will increase by 3 Tiddles in April")