Устаревание дебиторской задолженности в Excel VBA

Question

Я создал код vba для расчета отчета о дебиторской задолженности по возрасту, как показано на рисунке ниже.Но это занимает слишком много времени, чтобы завершить расчет.Буду признателен, если вы поможете мне оптимизировать этот код, чтобы ускорить расчет.

Таблица Excel выглядит следующим образом:

Мой код указан ниже:

Sub ARAgingSummary()
    Dim StartRow As Long
    Dim TotalDue As Double
    Dim BalanceDue As Double
    Dim L30 As Double
    Dim L60 As Double
    Dim L90 As Double
    Dim L120 As Double
    Dim O120 As Double
    Dim OpeningBal As Double

    Dim AL30 As Range
    Dim AL60 As Range
    Dim AL90 As Range
    Dim AL120 As Range
    Dim AO120 As Range
    Dim AOpeningBal As Range

    StartRow = 5
    Do Until Range("I" & StartRow) = ""

        Do Until Range("I" & StartRow) = ""

            TotalDue = Range("I" & StartRow).Value
            L30 = Range("B" & StartRow).Value
            L60 = Range("C" & StartRow).Value
            L90 = Range("D" & StartRow).Value
            L120 = Range("E" & StartRow).Value
            O120 = Range("F" & StartRow).Value
            OpeningBal = Range("G" & StartRow).Value

            Set AL30 = Range("J" & StartRow)
            Set AL60 = Range("K" & StartRow)
            Set AL90 = Range("L" & StartRow)
            Set AL120 = Range("M" & StartRow)
            Set AO120 = Range("N" & StartRow)
            Set AOpeningBal = Range("O" & StartRow)

            If L30 <= TotalDue Then
                AL30.Value = L30
                BalanceDue = TotalDue - L30
            ElseIf L30 > TotalDue Then
                AL30.Value = TotalDue
                Exit Do
            End If

            If L60 <= BalanceDue Then
                AL60.Value = L60
                BalanceDue = BalanceDue - L60
            ElseIf L60 > BalanceDue Then
                AL60.Value = BalanceDue
                Exit Do
            End If

            If L90 <= BalanceDue Then
                AL90.Value = L90
                BalanceDue = BalanceDue - L90
            ElseIf L90 > BalanceDue Then
                AL90.Value = BalanceDue
                Exit Do
            End If

            If L120 <= BalanceDue Then
                AL120.Value = L120
                BalanceDue = BalanceDue - L120
            ElseIf L120 > BalanceDue Then
                AL120.Value = BalanceDue
                Exit Do
            End If

            If O120 <= BalanceDue Then
                AO120.Value = O120
                BalanceDue = BalanceDue - O120
            ElseIf O120 > BalanceDue Then
                AO120.Value = BalanceDue
                Exit Do
            End If

            If OpeningBal <= BalanceDue Then
                AOpeningBal.Value = OpeningBal
                BalanceDue = BalanceDue - OpeningBal
                Exit Do
            ElseIf OpeningBal > BalanceDue Then
                AOpeningBal.Value = BalanceDue
                Exit Do
            End If

        Loop
        BalanceDue = 0
        StartRow = StartRow + 1
    Loop
End Sub

Это работает нормально, поскольку расчет важен, но время расчета очень велико.