(1) The weekly rate of pay-related benefit payable to a person in any period of interruption of employment shall be for any part of that period up to the 393rd day of unemployment (or in the case of a person to whom section 79(1)(b) applies, for any part of that period up to the 393rd day of incapacity for work), an amount equal to 12 per cent. of the part (if any) of his reckonable weekly earnings for the relevant income tax year that exceeds £80 but does not exceed such limit as stands prescribed for the time being, subject to such conditions as may be prescribed to restrict the total amount of benefit payable under this Part to the person in respect of any week.
(2) In the case of any entitlement to pay-related benefit payable in respect of a period of interruption of employment where -
(a) the period of interruption of employment commenced before the 8th day of April, 1991, subsection (1) shall be construed as if "£72" were substituted for "£80",
(b) the period of interrupt