Variable costs per item - Impact on reports / analytics

Hi everyone,

We are running our store so far without costs per item, though want to integrate the cost per item on a product basis in the very near future.

We do though wonder about the impact on our reporting due to the following reason.

Our product sales prices are changing more or less daily and our product costs per item are a percentage of our product sales price.
How does Shopify Analytics handle a change in the field cost per item?
Would Shopify automatically change the cost per item also in the reports of previously done sales or would those past costs per item remain the same and the costs reported would be always the costs at that point of time the sale was realized?

Thanks a lot for your feedback

Your HTV team