Aritmetično povprečje 10 let se ponderira po padajoči linearni lestvici, tako da ima razmerje ustreznega leta faktor ponderiranja 10, leto pred ustreznim letom ima faktor ponderiranja devet, naslednje predhodno leto ima faktor ponderiranja osem, in tako naprej, do 10. leta, ki ima faktor ponderiranja 1.
The arithmetic average of the ten years shall be weighted on a decreasing linear scale, so that the ratio of the relevant year shall have a weight of 10, the year prior to the relevant year shall have a weight of 9, the next preceding year shall have a weight of 8, and so on, until the tenth year has a weight of 1.