As a user of JIRA I would like the burn down chart to also plot a line representing the number of sub-tasks which are not yet done. For many sprints that have sub-tasks, the number of story points only starts to go down near the end of the sprint, e.g. due to testing that can only commence after development has been done first.

To match the scale of the story points, each sub-task would be reported as the number of story points for that user story divided by the number of sub-tasks for that user story. Stories without any sub-tasks would be reported as a single sub-task with the same amount of story points. Implementing this would give more insight of when progress is being made in a sprint.