Add an increasing subID to zoho reports database

Add an increasing subID to zoho reports database

Hi,

I have a Zoho reports database where I import data via APS from multiple sources.
For each row, I need to have an unique row ID which is +1 from the previous row.
On excel I could simply create a formula like B1=(A1+1) but I can't seem to do that on Zoho.
Any ideas?

Cheers,
Ian