1.—(1) Unless sub-paragraph (2) applies, the proportion of the billing authority’s non-domestic rating income in respect of the designated area for a specified year is the difference between the authority’s—
(a)non-domestic rating income in respect of the designated area for that year; and
(b)baseline amount in respect of the designated area for that year.
(2) If the baseline amount is greater than or equal to the non-domestic rating income, the proportion is zero.