Oh, and it's not mathematics ... it's arithmetic.Whatever you want to call it Lapdog, you still can't do it.
Well, Looey, at least one of us know what it IS ... and that one ain't you.
Your inimitable skill in Looey-rithmetic (a very specialized subset of arithmetic which is, in turn, a subset of mathematics) has been demonstrated many times on these threads along with that of some of the other SQL guys.
Seems that you and Nightie are locked in a battle for inaccuracy champion but - hate to tell you this, Looey - a few threads back he actually beat your 400% error figure by a few percentage points. Of course he has never owned up to HIS error either. At least yours was on a problem that you composed.