MS Access Rank GPA With Grouping

Question

我已经接近找到一个分组排名的答案但不完全。我有2张桌子

组织表

Chapter Council
DDD     IFC
DT      IFC
GG      IFC
AA      MGC
BB      MGC
CC      MGC
DD      IND
EE      IND

PSRoster

Chapter GRDPoints  TakeGPA  MemberName  Status
DDD    2.0           2         Bill     Active
DT     3.2           3         Jim      New Member
GG     4.0           6         Sue      New Member
AA     2.3           6         Jill     Active
BB     1.3           5         Joe      New Member
CC     3.2           5         Frank    Active
DD     3.2           4         Leslie   Active
EE     4.0           3         Sandra   Active

我必须动态计算每个章节的GPA，然后对它们进行排名并按理事会对它们进行分组。我没有问题计算GPA然后进行子查询以获得其他值，但我似乎无法使排名工作。下面是我的SQL。我缺少什么才能让理事会对GPA进行排名？

SELECT 
    Org.Council, 
    Org.Chapter, 
    Round((Sum(PSRoster.GrdPoints)/Sum(PSRoster.TakeGPA)),3) AS [Chapter Average],
    ( 
        Select Round((Sum(PSRoster.GrdPoints)/Sum(PSRoster.TakeGPA)),3) AS [Chapter Average] 
        FROM Org INNER JOIN PSRoster ON Org.Chapter = PSRoster.Chapter 
        WHERE PSRoster.Status = 'Active'  
    ) AS [Active Avg GPA],
    ( 
        Select Round((Sum(PSRoster.GrdPoints)/Sum(PSRoster.TakeGPA)),3) AS [Chapter Average] 
        FROM Org 
        INNER JOIN PSRoster ON Org.Chapter = PSRoster.Chapter 
        WHERE PSRoster.Status = 'New Member'  
    ) AS [New Member Avg GPA],
    (
        SELECT COUNT(PSRoster.Semester) AS [Total Number of 4] 
        FROM PSRoster 
        WHERE (PSRoster.Semester = 4.00  ) And Org.Chapter = PSRoster.Chapter 
    ) AS [FourOs]
FROM Org INNER JOIN PSRoster ON Org.Chapter = PSRoster.Chapter
Group By Org.Council, Org.Chapter;