Adjustment factor — other Category 1 oil
15.—(1) The adjustment factor for a Category 1 oil other than Brent blend is found as follows.
(2) Find the daily average of the differentials, from reference value, for the Category 1 oil in question quoted in the three relevant reports for each of the days—
(a)during the period which begins 21 days, and ends 14 days before the notional delivery day, and
(b)in respect of which at least one such report is produced.
(3) If any of the relevant reports contains more than one value for the Category 1 oil in question for any of these days, the result for that report for that day is the arithmetical mean of those values.
(4) Find the average of the daily averages found by paragraphs (2) and (3) for each of the days specified in paragraph (2).
(5) The result is the adjustment factor for the relevant Category 1 oil.