The weekly extended benefit amount payable to an individual for a week of total unemployment in his eligibility period shall be an amount equal to the weekly benefit amount payable to him during his applicable benefit year: Provided, That for any week during a period in which federal payments to states under section 204 of the Federal-State Extended Unemployment Compensation Act of 1970 are reduced under an order issued under section 252 of the Balanced Budget and Emergency Deficit Control Act of 1985, the weekly extended benefit amount payable to an individual for a week of total unemployment in his eligibility period shall be reduced by a percentage equivalent to the percentage of the reduction in the federal payment. Such reduced weekly extended benefit amount, if not a full dollar amount, shall be rounded to the nearest lower full dollar amount.