[PL\SQL] Increasing results

data

MNTH SM 1 10 2 20 3 30 4 40

WITH t AS (
SELECT 01 mnth,10 sm FROM dual UNION ALL
SELECT 02, 20 FROM dual UNION ALL
SELECT 03, 30 FROM dual UNION ALL
SELECT 04, 40 FROM dual
)
SELECT mnth, sm,
       SUM(sm) over(ORDER BY mnth ROWS UNBOUNDED PRECEDING) FROM t;

result

MNTH SM TOTAL 1 10 10 2 20 30 3 30 60 4 40 100