Courses - Last Control number isn't number of rows

[alago1]

I checked the API request against uf's portal course catalog and the last-control-number parameter does not seem to refer to the number of rows but rather the index to the next row.

Example:
The first call at the uf portal uses last-control-number=0.
The returned json has a LASTCONTROLNUMBER=3487.

The subsequent call when asking for rows 51-59 uses last-control-number=3487.
The returned json has a LASTCONTROLNUMBER=0 (no next row, references start).