Faster Way To Repeat Values Multiple Times

Hey,

I've got a list of about 62,000 values and I need to copy and add them to a row beneath. This needs to be done 15 times for each value.

I've achieved this with the code below, but at a rough estimation it will take about 8 or 9 hours to complete. I'm just wondering if there is a quicker and more efficient way to do it by any chance?

Sub test()
' Get last row
intLastRow = ActiveSheet.Range("A" & Rows.Count).End(xlUp).Row

' Loop till last row
intRow = 0
For Each strColAValue In ActiveSheet.Range("A1:A" & intLastRow).Value
    intRow = intRow + 1

    ' If found year, insert row below
    If InStr((strColAValue), "") > 0 Then
        Range("A" & intRow + 1).Select
            For I = 1 To 15
                Selection.EntireRow.Insert
                Selection.FormulaR1C1 = "=REPT(R[-1]C,1)"
                intRow = intRow + 1
            Next I
    End If

Next

End Sub

Thanks for the help!

Josh.