For Each cell In wb.Sheets("RP Analysis").Range("F5:F" & lastRow)
structure = "Layer " & WorksheetFunction.RoundDown(cell.Value, 2) & ": " & WorksheetFunction.RoundDown(cell.Offset(0, 2).Value / 1000000, 2) & " xs " & WorksheetFunction.RoundDown(cell.Offset(0, 3).Value / 1000000, 2) & " attaches at "
RMS = RMS & structure & WorksheetFunction.RoundDown(cell.Offset(0, 10).Value, 2) & "m and exhausts at " & WorksheetFunction.RoundDown(cell.Offset(0, 11).Value, 2) & "m" & vbLf
AIR = AIR & structure & WorksheetFunction.RoundDown(cell.Offset(0, 6).Value, 2) & "m and exhausts at " & WorksheetFunction.RoundDown(cell.Offset(0, 7).Value, 2) & "m" & vbLf
Next cell
For Each cell In wb.Sheets("RP Analysis").Range("A9:A" & 19)
gucurve = gucurve & cell.Value & ":- " & Format(cell.Offset(0, 2).Value / cell.Offset(0, 1).Value, "Percent") & vbLf
Next cell
TextBox1.Value = "RP years RMS/AIR difference" & vbLf & gucurve & vbLf & "AIR" & vbLf & AIR & vbLf & "RMS" & vbLf & RMS
For Each cell In wb.Sheets("RP Analysis").Range