Best practice when editing Offer Letters for new hires

We are curious as to what the best practice is for editing offer letters so that we have history of changes that were made to the offer letter. It would also be nice to have the ability to add a reason why the applicant rejected the initial offer.

We know that we can edit or delete and offer letter, and that the offer letters are saved on the manage applicant page but we would prefer not to have to open multiple offer letters to see what the changes are that were made.

Maybe there is a table that we can query from that stores this information we can use. I tried to query the following table: HRS_OFF_DTL_HST but there was not data on this table. Maybe I need to talk to our IT dept to see if they need to turn something on to track the changes in this table.