The SQL query below can be used to count how many cancelled bookings exist from a particular date, and give a total per user.
Simply cut/paste the query text below into the SQL tool, and give the query a NAME so that you can save it.
SELECT BKNG_BOOK_TYPE, BKNG_CREATED_BY, COUNT(BKNG_UNIQ_ID) as'Qty' FROM BKNGTAB0001
WHERE BKNG_DATE>'2019-06-01' and BKNG_BOOK_TYPE like 'CA%'
GROUP BY BKNG_CREATED_BY
NOTE: The query above assumes that your CANCELLATIONS use a booking type of CAN (or anything else starting CA.... )
When using the query you would need to amend the booking dates shown (e.g. '2019-06-01') to show the date from which you want to see any cancellations.