以下语句出错，求助！（将成绩的前20%转化为A的自定义函数）

试一下：

Function cjdjhs(X As Single) As String
    Dim Y As DAO.Recordset
    Dim Y20 As Single
    Dim Y50 As Single
    Dim Y80 As Single
   
    set Y = CurrentDb.OpenRecordset("SELECT Count(成绩记录表.学号) AS [总人数] FROM 成绩记录表;")
    If Y.RecordCount > 0 Then                         
        Y20 = Y.Fields("[总人数]") * 0.2
        Y50 = Y.Fields("[总人数]") * 0.5
        Y80 = Y.Fields("[总人数]") * 0.8
        If X <= Y20 Then
            cjdjhs = "A"
        End If
        If X > Y20 And X <= Y50 Then
            cjdjhs = "B"
        End If
        If X > Y50 And X <= Y80 Then
            cjdjhs = "C"
        End If
        If X >= Y80 Then
            cjdjhs = "D"
        End If
    END IF
End Function