WITH TMP AS (
SELECT
    MIN(MONTHLY) YM,
    0 MRR
FROM
    MRR_DATA
UNION ALL
SELECT
    DATE(YM, '+1 month') YM,
    MRR + (
        SELECT M.NEW_MRR + M.EXPANSION_MRR - M.DOWNGRADE_MRR - M.CHURN_MRR
        FROM MRR_DATA M
        WHERE M.MONTHLY = YM
    ) AS MRR
FROM
    TMP T
WHERE YM <= (SELECT MAX(MONTHLY) FROM MRR_DATA)
)

SELECT *
FROM
    TMP
ORDER BY
    YM