In Fuentes v. Workers' Comp. Appeals Bd. (1976) 16 Cal.3d 1, the injured worker sustained an industrial injury to his lungs after April 1, 1972. While his total permanent disability rated at 58 percent permanent disability only 33.75 percent permanent disability was industrially related. The court applied section 4658 by computing the industrial disability at the bottom of the graduated scale. The court held that this method was required by Labor Code section 4750 which states: "An employee who is suffering from a previous permanent disability or a physical impairment and sustains permanent injury thereafter shall not receive from the employer compensation for the later injury in excess of the compensation allowed for such injury when considered by itself and not in conjunction with or in relation to the previous disability or impairment. The employer shall not be liable for compensation to such an employee for the combined disability, but only for that portion due to the later injury as though no prior disability or impairment had existed." The court in Fuentes acknowledged that by their application of section 4658 an injured worker who sustained one injury which resulted in 50 percent permanent disability would receive greater benefits than one who sustained two successive injuries each of which causes a permanent disability of 25 percent when considered alone. The court viewed the result as "neither unjust nor unfair" but "rather, it is a consequence of the recent amendments to section 4658 and is consistent with the . . . policy of 4750 of encouraging employers to hire the disabled." ( Fuentes, supra, 16 Cal.3d at p. 8.)