Capturing Change in Margin in the Project Budget Approval Notification

Summary: We wish to capture the Change in Margin Percent in the email notification for Budget approvals.

Change =Margin Percent of Baselines Version- Margin Percent of Current Version

Content (required): When we try to modify the notification template using the template builder for Word and when we click on 'Insert Field', we do not get any option for Margin Change.

If at least we can insert the margin percent field from baselined versions then we can manage the calculation of the change on our own. But we do not see any option for previous versions as well.

How can we achieve this?