Need e-mail merge field for "previous attendees".

This is in reference to ticket ENSD-59124 I submitted, but was directed to submit a user voice. On the "Change in Booking" e-mail notification, there is a mail-merge field for number attending, but not previous number attending. Our Hospitality team would really like a merge-field for that. A lot of other data points have a "previous" version so we hope this is pretty simple to accomplish.