SELECT Month, ROUND(Sales,0)/1000 AS M_Sales, 
    ROUND(AVG(Sales)
        OVER (ORDER BY Month ROWS BETWEEN UNBOUNDED PRECEDING 
                   AND CURRENT ROW),0)/1000 AS Moving_Avg_M_Sales
FROM (
            SELECT monthnumberofyear AS Month, 
                        ROUND(SUM(transactionprice*quantity),0) AS Sales 
            FROM factonlinesales fos INNER JOIN dimdate dd
                ON fos.orderdatekey= dd.datekey
            WHERE calendaryear = 2024
            GROUP BY monthnumberofyear
            )
ORDER BY 1, 2 ;