Between 2018 and 2023, the average retail price of biodegradable plant-based laundry pods in the UK increased from £32.40 per bulk pack to £38.50 per bulk pack. Over the same period, the annual quantity of bulk packs purchased fell from 4.5 million packs to 3.6 million packs.
Calculate the change in total sales revenue for UK biodegradable laundry pod retailers between 2018 and 2023. You are advised to show your working.
