桌子上3个月的滚动平均值

Question

查询到目前为止：

    SELECT Month
      ,Year
      ,vol
      --sum(vol) over (order by month,year  ROWS BETWEEN 2 PRECEDING AND current row) sumnetvol,
      ,AVG(vol) OVER (ORDER BY Month, Year ROWS BETWEEN 2 PRECEDING AND CURRENT ROW) '3monthra'
      ,name
      ,cnt
      ,costx
FROM(SELECT MONTH(CONVERT(DATETIME, CAST(monthnumber AS NVARCHAR(10)) + '01')) AS [Month]
           ,YEAR(CONVERT(DATETIME, CAST(monthnumber AS NVARCHAR(10)) + '01')) AS [Year]
           ,SUM(SumOfNetAmount) AS vol
           ,COUNT(*) AS cnt
           ,costx
           ,name
     FROM [ngl_OTB]
     GROUP BY costx
             ,MONTH(CONVERT(DATETIME, CAST(monthnumber AS NVARCHAR(10)) + '01'))
             ,YEAR(CONVERT(DATETIME, CAST(monthnumber AS NVARCHAR(10)) + '01'))
             ,name
             ,SumOfNetAmount) s
WHERE costx = '1000.002'
    AND name = 'ngl-raw'
ORDER BY Month
        ,Year

我需要有关如何递归设置[costx]和[name]列的帮助，以允许三个月正确滚动每个[costx]和[name]的平均值。所有尝试都提供了错误的计算方法，例如3个月的平均滚动平均值正在渗入其他costx和名称。我的目标是将所有数据按costx分组，并按年份和月份对名称和顺序进行分组，然后使用该[costx]的[vol]值对每个costx进行平均3个月的平均滚动。