Listbox Array calculation by first column

[asyamonique]

Column A	Column B											Column M	Column N
MONTH	DATE	CUSTOMER ID#	FIRST NAME	LAST NAME	DATA	DATA	DATA	DATA	DATA	DATA	DATA	POINTS	POINTS	DATA
June	7-Jun-2018											5,000	8,000
June	7-Jun-2018											5,100	8,100
June	7-Jun-2018											5,200	8,200
June	7-Jun-2018											5,300	8,300
June	7-Jun-2018											5,400	8,400
June	8-Jun-2018											5,500	8,500
June	8-Jun-2018											5,600	8,600
June	8-Jun-2018											5,700	8,700
June	8-Jun-2018											5,800	8,800
June	8-Jun-2018											5,900	8,900
June	8-Jun-2018											6,000	9,000
July	5-Jul-2018											6,100	9,100
July	5-Jul-2018											6,200	9,200
July	7-Jul-2018											6,300	9,300
July	8-Jul-2018											6,400	9,400
July	9-Jul-2018											6,500	9,500
July	9-Jul-2018											6,600	9,600
July	9-Jul-2018											6,700	9,700
August	3-Aug-2018											6,800	9,800
August	3-Aug-2018											6,900	9,900
August	3-Aug-2018											7,000	10,000
August	3-Aug-2018											7,100	10,100
August	7-Aug-2018											7,200	10,200
August	7-Aug-2018											7,300	10,300

<colgroup><col><col><col><col span="2"><col><col span="2"><col span="2"><col><col span="3"><col></colgroup><tbody>
</tbody>

Hello above data filtering by below code from first column,

Private Sub ComboBox2_Change()



Dim a, i As Long, ii As Long, b(), n As Long
ListBox1.Clear
With ComboBox2


If .Text = "" Then Exit Sub
If WorksheetFunction.CountIf(Worksheets("list").Range("a:a"), .Text) = 0 Then


Exit Sub
End If
a = Worksheets("list").Range("a1").Resize(Worksheets("list").Range("a" & Rows.Count).End(xlUp).Row, 15).Value
For i = 1 To UBound(a, 1)
If a(i, 1) = .Text Then
n = n + 1: ReDim Preserve b(1 To 15, 1 To n)
For ii = 1 To UBound(a, 2)
b(ii, n) = a(i, ii)
Next
b(2, n) = Format$(a(i, 2), "dd-mmm-yyyy")
'b(5, n) = Format$(a(i, 5), "h:mm")
End If
Next
End With
With ListBox1
.ColumnCount = 15
.ColumnWidths = "0;60;60;120;120;0;0;0;0;0;0;0;100;100;0"
.Column = b
End With
End Sub

Is it possible to filter those datas into the listbox as given table below?
Column M and Column N values will sum base on column A data.
If I select June the list must populate as given table.
Many Thanks

MONTH

DATE

CUSTOMER ID#

FIRST NAME

LAST NAME

DATA

DATA

DATA

DATA

DATA

DATA

DATA

POINTS

POINTS

DATA

June

7-Jun-2018

26,000

41,000

June

8-Jun-2018

34,500

52,500

July

5-Jul-2018

12,300

18,300

July

7-Jul-2018

6,300

9,300

July

8-Jul-2018

6,400

9,400

July

9-Jul-2018

19,800

28,800

August

3-Aug-2018

27,800

39,800

August

7-Aug-2018

21,800

20,500

<colgroup><col><col><col><col span="2"><col><col span="2"><col span="2"><col><col span="3"><col></colgroup><tbody>
</tbody>