How to know number of days between Deal Stages?

How to know number of days between Deal Stages?

Hi Team - how do I know the number of days between Deal Stages? I have a Deal blueprint and I want to know the number of days it takes the Deal to be on Stage 3 to Stage 8? I can't seem to create a report for that.

Our Deals have 11 Stages and our Purchasing department is in charge of Stage 3 to Stage 8 and I want to know the number of days it takes for them to complete their stages?