Sub SupprimerLignes()
Dim tablo, i&, j&
Application.ScreenUpdating = False
With ActiveSheet.UsedRange.Offset(1) 'saute la ligne des en-têtes
With .Resize(12 * Int(.Rows.Count / 12) + 12) 'multiple de 4 + 8 = 12
.Columns(1).EntireColumn.Insert 'colonne auxiliaire
tablo = .Columns(0) 'matrice, plus rapide
For i = 1 To UBound(tablo) Step 12
For j = i To i + 3
tablo(j, 1) = 1 'repère
Next j, i
With .Columns(0)
.Value = tablo
.EntireRow.Sort .Cells, Header:=xlNo 'tri pour regrouper et accélérer
.SpecialCells(xlCellTypeBlanks).EntireRow.Delete
.EntireColumn.Delete
End With
End With
End With
End Sub