Snapshot error on first record

Hi,

I am trying to make a field that automatically counts up (similar to record ID, but where it starts new for each project). I am using the snapshot function to accomplish this. It works fine, except for on the first iteration.

I have 2 tables, Projects and Request for Information (RFI). Projects is the parent to RFI.

I have a summary field that is the maximum RFI Number.
I have a lookup field in the RFI table, of that summary field.
In the RFI table I have a snapshot field, that snapshots the lookup field mentioned above.
And finally on the RFI table I have a formula numeric field (RFI number) which is Snapshot Field +1

When I add a new RFI, it shows everything correct. Snapshot = 0, RFI number =1. As soon as I save, it adjusts and becomes snapshot =1, RFI number = 2.

After that it works perfectly. How can I get the first RFI to number correctly?

Thank you