At the end of each year, I often face a practical problem: I need to allocate the annual sales difference across four quarters. However, I do not want to use an equal distribution method. If the difference is allocated proportionally to each quarter's sales as a share of total sales, then quarters with higher sales (which usually means their sales records are more complete and accurate) would be allocated more of the difference, which seems unreasonable.

Therefore, I want to find a formula or method that achieves the "reverse" effect: the higher the recorded sales in a quarter, the smaller the difference it should be allocated. In other words, the allocation ratio should be inversely proportional to quarterly sales, not directly proportional.

Is there such a mathematical formula or statistical method? If so, how should it be constructed or applied?