Add API to track time how long (in days) a candidate stays at a particular stage

We want to assess how long (in days) a candidate stays at a particular stage in the process of closing a vacancy.
We want to retrieve this data via API in BI, where we will generate the report we need.
What we need from you:
Information about where this data can be requested and retrieved through the API.

Request in FeatureOS about this specific functionality.

Similar request (but with wider functionality) for enriching reports functionality with API on each application history.