4. For the purposes of section 6(1) of the 1975 Act, the aggregate amount of the rateable values of generation lands–
(a)for the financial year 2000-01, is hereby prescribed as £72,253,000;
(b)for each of the following four financial years, shall be ascertained by adding together the amounts apportioned in respect of generation lands occupied by each Company for the year in question (calculated as provided for in article 5(2) below).