Insert Missing Years between 2 years - excel

Question

I have code that will insert the number of rows based on data missing between 2 numbers but I am unable to figure out the code to get it to copy and paste the years I am missing.
Thanks in advance for any help, I am pretty good at manipulating existing code but I can't find any code to add to this to make it work
Here is the code I have to insert the right number of blank rows
Public Sub Insert()
Application.ScreenUpdating = False
Application.Calculation = xlCalculationManual 'pre XL97 xlManual
lastRow = ActiveSheet.UsedRange.Rows.Count
ActiveSheet.Cells(lastRow, 1).Select
Set CurrentCell = ActiveSheet.Cells(lastRow, 1)
For n = lastRow To 0 Step -1
If n = lastRow Then GoTo CheckLastRow
If n = 1 Then GoTo CheckfirstRow
ActiveCell.Offset(-2, 0).Select
CheckLastRow:
Set NextCell = CurrentCell.Offset(-1, 0)
ActiveCell.Offset(1, 0).Select
For i = 1 To CurrentCell
ActiveCell.EntireRow.Insert
Next i
Set CurrentCell = NextCell
Next n
'To be performed on the firstrow in the column
CheckfirstRow:
ActiveCell.Offset(-1, 0).Select
For i = 1 To CurrentCell
ActiveCell.EntireRow.Insert
Next i
Application.Calculation = xlCalculationAutomatic
Application.ScreenUpdating = True
End Sub
My data looks like this
Column A is number of Rows I need Column B&C has years
B = 2009
C = 2013
It would need the output to copy the line and look like
2009 2010
2010 2011
2011 2012
2012 2013
I added this to the code and I still only have blank lines
Public Sub InsertTest()
Application.ScreenUpdating = False
Application.Calculation = xlCalculationManual 'pre XL97 xlManual
lastRow = ActiveSheet.UsedRange.Rows.Count
ActiveSheet.Cells(lastRow, 1).Select
Set CurrentCell = ActiveSheet.Cells(lastRow, 1)
For n = lastRow To 0 Step -1
If n = lastRow Then GoTo CheckLastRow
If n = 1 Then GoTo CheckfirstRow
ActiveCell.Offset(-2, 0).Select
CheckLastRow:
Set NextCell = CurrentCell.Offset(-1, 0)
ActiveCell.Offset(1, 0).Select
For i = 1 To CurrentCell
ActiveCell.EntireRow.Insert
Next i
With Worksheets("Sheet1")
newYear = .Cells(n, 2).Value
YearDifference = .Cells(n, 3).Value - newYear
For j = 0 To YearDifference - 1
.Cells(n + j, 2).Value = newYear
newYear = newYear + 1
.Cells(n + j, 3).Value = newYear
Next j
End With
Set CurrentCell = NextCell
Next n
'To be performed on the firstrow in the column
CheckfirstRow:
ActiveCell.Offset(-1, 0).Select
For i = 1 To CurrentCell
ActiveCell.EntireRow.Insert
Next i
Application.Calculation = xlCalculationAutomatic
Application.ScreenUpdating = True
End Sub

Answer 1

TESTED
First off, you should always avoid using Select and ActiveCell as described here.
Try adding the following loop before your Set CurrentCell = NextCell line:
With Worksheets("Sheet1")
newYear = .Cells(n, 2).Value
YearDifference = .Cells(n, 3).Value - newYear
For j = 0 To YearDifference - 1
.Cells(n + j, 1).Value = .Cells(n, 1).Value
.Cells(n + j, 2).Value = newYear
newYear = newYear + 1
.Cells(n + j, 3).Value = newYear
Next j
End With
You'll need to change the sheet reference as necessary and you should dimension the variables at the beginning of your code.
EDIT
Replace your code with this and it should work:
Sub InsertTest()
Dim LastRow As Long
Dim newYear As Long
Dim YearDifference As Long
Dim n As Long, j As Long
Application.ScreenUpdating = False
Application.Calculation = xlCalculationManual
With Worksheets("Sheet1")
LastRow = .Cells(Rows.Count, 2).End(xlUp).Row
For n = LastRow To 1 Step -1
If n Mod 10 = 0 Then DoEvents
If .Cells(n, 1).Value <> "" Then
newYear = .Cells(n, 2).Value
YearDifference = .Cells(n, 3).Value - newYear
If YearDifference > 1 Then
Application.StatusBar = "Updating Row #" & n
.Range(.Cells(n + 1, 1), .Cells(n + YearDifference - 1, 15)).Insert Shift:=xlDown, CopyOrigin:=xlFormatFromLeftOrAbove
For j = 0 To YearDifference - 1
.Rows(n + j).Value = .Rows(n).Value
.Cells(n + j, 2).Value = newYear
newYear = newYear + 1
.Cells(n + j, 3).Value = newYear
Next j
End If
End If
Next n
End With
Application.StatusBar = False
Application.ScreenUpdating = True
Application.Calculation = xlCalculationAutomatic
End Sub
EDIT 2 - The code now includes a DoEvents line that runs every 10 iterations. This frees up some resources so that the code will run in the background. For a sheet with 27,000 rows like yours, it may take a couple hours to run the code, but you should be able to do other things in the meantime. I've also added a line to update the status bar so you can see which row the code is on.