SELECT
t1.YEAR_MONTH,
t1.MONTH_AMT,
SUM(MONTH_AMT) OVER (ORDER BY t1.YEAR_MONTH ASC) AS CUML_AMT,
YEAR_MOVE_AMT
FROM
(SELECT
strftime('%Y-%m',SALES_DATE ) AS YEAR_MONTH,
SUM(SALES_AMT) AS MONTH_AMT
FROM
SALES
WHERE
UPDATED_NO IS NULL
AND
SALES_DATE >= '2023-01-01'
GROUP BY
YEAR_MONTH) t1

INNER JOIN
(SELECT
strftime('%Y-%m',SALES_DATE ) AS YEAR_MONTH,
/*SUM(SALES_AMT) AS MONTH_AMT,*/
SUM(SALES_AMT) OVER (ORDER BY strftime('%Y-%m',SALES_DATE ) ASC ROWS 11 PRECEDING) AS YEAR_MOVE_AMT
FROM
SALES
WHERE
UPDATED_NO IS NULL
GROUP BY
YEAR_MONTH) t2
ON
t1.YEAR_MONTH = t2.YEAR_MONTH
ORDER BY
t1.YEAR_MONTH