Sub (Test) 
   Application.ScreenUpdating = False
    Dim LastColumn, LastRow As Integer
    Cells.MergeCells = False
    Rows("1:3").Delete Shift:=xlUp
    Columns("A:A").Delete Shift:=xlToLeft
    LastColumn = Range("IV1").End(xlToLeft).Column
    LastRow = Range("A65536").End(xlUp).Row + 1
    
    For i = 2 To (LastColumn + LastColumn - 1) Step 2
        Columns(i + 1).Insert
        Cells(1, i + 1).Value = "% of Grth"
        Columns(i + 1).NumberFormat = "0%"
    ''
    LastColumn = Range("IV1").End(xlToLeft).Column
    '''
        Cells(LastRow - 1, i + 1).FormulaR1C1 = "=RC[-1]/" & (LastColumn)
        Cells(LastRow - 1, i + 1).Select
        Selection.AutoFill Destination:=Range(Cells(2, i + 1), Cells(LastRow - 1, i + 1)), Type:=xlFillDefault
    Next i
    
    Columns(LastColumn + LastColumn - 1).Delete
End sub