External task execution duration

Camunda version: 7.11
I need to get the exection time duration of a an external task. The start time would we when the worker do a fetch/lock and the end time would be the when the worker complete the task. Is there a way to get this info out of the camunda DB or Rest API. Note, I believe that this cannot be the start and end time on ACT_HI_PROCINST since the task might be sitting and waiting for a worker to pick up the task and start executing it.
Thank you.