we have purchased your self-hosted version of Invoice Ninja. We are trying to extract a report that will assist us in finding out which products are the most popular in our product range. Is it possible to extract an report which is grouped by product code and has the sum of line totals for that specific product? We managed to successfully draw a report that is grouped by product code but only exposes the fields Quantity and Cost. How can we get the sum of all line items for a specific product code? Is that possible?