14In respect of the financial year 1993-94 and each subsequent financial year, each local authority shall, before such date as may be prescribed in relation to each of those years—
(a)subject to paragraph 15 below, estimate the amount of the expenditure mentioned in paragraph 13 above which they will incur in respect of that year; and
(b)subject to paragraphs 16 and 17 below, determine what proportion of that expenditure is to be met out of—
(i)the council tax; and
(ii)the said non-domestic sewerage rate,
respectively.