Split and simplify the following sentence while retaining its full meaning: Whereas the developments on the tuna market since the fixing of the conversion factors have brought about a change in the commercial value ratio between the products concerned and the pilot product; whereas this state of affairs calls for the conversion factors in question and the products for which they are specifically intended to be reviewed.
 Simplified version:
The development of the situation on the tuna market since these coefficients were set has resulted in a change in the relationship between the commercial value of the products and that of the conductor product . This situation justifies a change in the relevant coefficients and a review of the products for which they are specifically determined .