1. Any claimant or dependent of a claimant who is receiving compensation pursuant to chapters 616A to 616D, inclusive, of NRS for a permanent total disability but is not entitled:
(a) To an increase in that compensation pursuant to NRS 616C.455; or
(b) To any disability income benefits from the federal social security system,
Ê is entitled to an increase in that compensation by the same percentage as the increase in the state average monthly wage from the date of the claimant’s disabling accident or disease or from July 1, 1973, whichever is later, to July 1, 1980.
2. The increase provided by this section must not be paid for any period before July 1, 1981.