[RESOLVED] vb.net improve programs

[eurostar_italia]

I,i have a little program that retrieves railway reservations for groups.
it downloads from a website getting a json.I store data in a matrix.
The object for the program is to know :
a) how many station are served from that train
b) how many people load and unload that train,selecting a particular station (ex rome,11 loaded,89 unloaded)
c) how many people load a specific car (ex car 5-10 passenger,car 7-11 passenger)
d) how many destinations and people selecting a particular station (ex from rome,11 passenger to florence,18 to milan,etc)
i have a matrix with 14 columns and setted with 5000 rows (i don't think the will be more).
i made a lot of inquiries with a for next to have all this informations,but some need a lot of time to get a response
my progam run in a company computers so i can't install or set anything,i can just place my exe on the computer.
in your opinion,wich would be the best way to improve my program ? datatable ? sql ?
thank for you cooperation
this is my code :
json download to the matrix (stands for bidimensional array)
i use newtonsoft json library

	Public matrice(5000, 15) As String
	Public matrice2(5000, 15) As String
	Public matrice3(5000, 15) As String
	Dim listadest As New List(Of Destinazioni)
	Dim listacar As New List(Of paxincarrozza)
	Dim listapax As ArrayList = New ArrayList
	
	Dim listapaxcognomi As ArrayList = New ArrayList

Dim ser As JObject = JObject.Parse(json)

			Dim data As List(Of JToken) = ser.Children().ToList



			If chiamata = 1 Then
				For Each item As JProperty In data
					item.CreateReader()

					For Each msg As JObject In item.Values

						matrice(contatore, 0) = msg("departureLocationName")
						matrice(contatore, 1) = msg("arrivalLocationName")
						matrice(contatore, 2) = msg("pnrCode")
						matrice(contatore, 3) = msg("serviceLevel")
						matrice(contatore, 4) = msg("lastName")
						matrice(contatore, 5) = msg("wagon")
						matrice(contatore, 6) = msg("seat")
						matrice(contatore, 7) = msg("firstName")
						matrice(contatore, 8) = msg("transportMeanName")
						matrice(contatore, 9) = msg("couponId")

						contatore = contatore + 1


					Next
				Next

				contatore = 0
				
				Do
					If ComboBox1.Items.IndexOf(matrice(contatore, 0)) = -1 Then
						ComboBox1.Items.Add(matrice(contatore, 0))
					End If
					If ComboBox1.Items.IndexOf(matrice(contatore, 1)) = -1 Then
						ComboBox1.Items.Add(matrice(contatore, 1))
					End If

					contatore = contatore + 1
				Loop Until matrice(contatore, 0) = Nothing

				Label1.Text = "TRENO  " & (matrice(0, 8))

then to know passenger destination or passenger load for single car :

		ListBox2.Items.Clear()

		Dim i1 As Integer

		Dim prima1 As Boolean = True
		Dim appoggio1 As paxincarrozza
		listacar.Clear()

		For i1 = 1 To 4999

			If ComboBox1.SelectedItem = (matrice(i1, 0)) Then
				If prima1 = True Then

					appoggio1.carrozza = (matrice(i1, 5))
					appoggio1.quantita = 0
					listacar.Add(appoggio1)


					prima1 = False
				End If
				Dim appo1 As New List(Of paxincarrozza)
				appo1.AddRange(listacar)
				Dim trovato As Boolean = False

				Dim a As Integer
				For Each element As paxincarrozza In appo1

					If element.carrozza = matrice(i1, 5) Then
						trovato = True
						a = listacar.IndexOf(element)
						appoggio1 = element
					End If

				Next

				If trovato = True Then
					appoggio1.quantita = appoggio1.quantita + 1
					listacar(a) = appoggio1
				Else

					appoggio1.carrozza = (matrice(i1, 5))
					appoggio1.quantita = 1
					listacar.Add(appoggio1)
				End If



			End If
		Next
		ListBox2.Items.Clear()

		For Each element As paxincarrozza In listacar
			ListBox2.Items.Add(element.carrozza & "   -   " & element.quantita)

		Next

the point is : a datatable with sql query would be better in your opinion ? or it just load memory without any speed increase ? i'm not sure about it.
we are speaking about 5000 rows nothing more...
thanks to all of you