I'm going to be kind to them and assume they are using the AI to augment the obviously simple "rating delta over time" I'd do as the first pass solution. Like

I'm going to be kind to them and assume they are using the AI to augment the obviously simple "rating delta over time" I'd do as the first pass solution. Like "Over a 3 month period this product reviewed at 3.7 and the next 2.1" maybe look into why.