37PStep 8—Weighted average percentage difference of brands of pharmaceutical item

#### 37P Step 8—Weighted average percentage difference of brands of pharmaceutical item (1) Work out the weighted average percentage difference of the brands of the pharmaceutical item. (2) The weighted average percentage difference is: (a) if the total adjusted volume of the brands of the pharmaceutical item (see step 7) is zero or less—zero; or (b) if the total adjusted volume of the brands of the pharmaceutical item (see step 7) is more than zero—the amount (expressed as a percentage to 2 decimal places) worked out by: (i) for each brand of the pharmaceutical item, multiplying the adjusted volume of the brand for the brand’s data collection period (see step 2) by the price percentage difference of the brand for the data collection period (see step 5); and (ii) adding up each of those amounts; and (iii) dividing that amount by the total adjusted volume of the brands of the pharmaceutical item.