You might try using this SQL query; just change the 7 days for 30 days.
Hope this works.
Here is a useful link with many SQL queries.
https://github.com/thobiast/tsm_sql
12.3. Statistics of archive, backup, restore and retrieve operations per node in the last 7 days (GB)
TSM version 6
SELECT entity, activity, CAST(FLOAT(SUM(bytes)) / 1024 / 1024 / 1024 AS DECIMAL(8,2)) -
FROM summary
WHERE DAYS(current_timestamp)-DAYS(end_time)<=7 and ( activity='ARCHIVE' OR -
activity='BACKUP' OR activity='RESTORE' OR activity='RETRIEVE' )
GROUP BY entity, activity
TSM version 5
SELECT entity, activity, CAST(FLOAT(SUM(bytes)) / 1024 / 1024 / 1024 AS DECIMAL(8,2)) -
FROM summary
WHERE end_time>current_timestamp-(7)DAY and ( activity='ARCHIVE' OR -
activity='BACKUP' OR activity='RESTORE' OR activity='RETRIEVE' )
GROUP BY entity, activity