WITH T1 AS(
    SELECT
        SUBSTR(SALES_DATE, 1, 7) AS YEAR_MONTH,
        SUM(SALES_AMT) AS MONTH_AMT
    FROM
        SALES
    WHERE
        UPDATED_NO IS NULL
    GROUP BY
        SUBSTR(SALES_DATE, 1, 7)
), T2 AS(
    SELECT
        YEAR_MONTH,
        MONTH_AMT,
        SUM(MONTH_AMT) OVER(
            ORDER BY YEAR_MONTH ASC
            ROWS BETWEEN 11 PRECEDING AND 0 PRECEDING
        ) AS YEAR_MOVE_AMT
    FROM
        T1
), T3 AS(
    SELECT
        *
        FROM T2
    WHERE
        YEAR_MONTH BETWEEN '2023-01' AND '2023-12'
), T4 AS(
    SELECT
        YEAR_MONTH,
        MONTH_AMT,
        SUM(MONTH_AMT) OVER(
            ORDER BY YEAR_MONTH ASC
        ) AS CUML_AMT,
        YEAR_MOVE_AMT
    FROM T3
    ORDER BY YEAR_MONTH
)

SELECT
    *
    FROM T4