JQL for Dataplane Report for data when an issue was a certain status and unassigned

[Sheila Marshall]

I'm trying to figure out HOw to gather data in a Dataplane Graph for: Time from Assigned to IN progress, where Assigning a person to an issue happens while the issue is in a Ready status

This basically what I want but I don't know what to use to express the "when" part of the query.

Project = SDCD AND issuetype = "Customer Interaction" AND Status NOT IN (Cancel, Cancelled) AND (ASSIGNEE WAS NOT EMPTY WHEN Status was ready)

Here's the dataplane UI

Any help is greatly appreciated!