VBA Dynamic Chart Not Working Properly

[SouthernGent0327]

So I have the following sample set:

Days of Operation	Packages
10	20
15	50
18	100

The workbook is setup to take in data from a UserForm and formulas transfer this data to a dummy range for graphing. There are multiple ranges like shown above starting at Row 12 to 2015. Here is the current code used to generate the XY scatter Plots:

Sub NormPerm1()
Dim ws As Worksheet
Dim NormPRange As Range
Dim NormPChart As Chart
Dim LastRow As Long
Dim StartCell As Range

Set ws = ActiveSheet
Set StartCell = Range("AG12")

ActiveSheet.UsedRange

Set NormPChart = Charts.Add

LastRow = ws.Cells.Find("*", searchorder:=xlByRows, searchdirection:=xlPrevious).Row

Set NormPRange = ws.Range("AG12:AG" & LastRow & ", AH12:AH" & LastRow)

With NormPChart

.SetSourceData Source:=NormPRange
.HasTitle = True
.ChartTitle.Text = "Normalized Permeate Flow"
.ChartType = xlXYScatter
.PlotBy = xlColumns

End With


End Sub

Currently, the graphing function works, but the X-axis is arbitrarily graphing values on the X-axis. So effectively just counting the entries and not actually using the correct days of operations values. How can I make the x and y axis dynamically update as new data is added to the table? Also, is this the best way of accomplishing my goal or would an alternate method work better for this application? Thanks in advance for your time and help. Also, here is a copy of the output from the full scale table:

That x-axis should be values ranging from 13 to 600 days.

 

[SouthernGent0327]

Dim sht As Worksheet
Dim LastRow As Long
Dim LastColumn As Long
Dim StartCell As Range

Set sht = ActiveSheet
Set StartCell = Range("AG12")

'Refresh UsedRange
  ActiveSheet.UsedRange

'Find Last Row
  LastRow = sht.Cells.Find("*", searchorder:=xlByRows, searchdirection:=xlPrevious).Row

'Select Range
  sht.Range("AG12:AG" & LastRow).Select
  
  Charts.Add

Here is the correct code, the graph orientation is correct, only the x values displayed are the number of points and not actual data points.

 

[SouthernGent0327]

Dim ws As Worksheet
Dim NormPRange As Range
Dim NormPChart As Chart
Dim LastRow As Long
Dim StartCell As Range

Set ws = ActiveSheet
Set StartCell = Range("AG12")

ActiveSheet.UsedRange

Set NormPChart = Charts.Add

LastRow = ws.Cells.Find("*", searchorder:=xlByRows, searchdirection:=xlPrevious).Row

Set NormPRange = ws.Range("AG12:AG" & LastRow & ", AH12:AH" & LastRow)

With NormPChart
    .SetSourceData Source:=NormPRange
    .HasTitle = True
    .ChartTitle.Text = "Normalized Permeate Flow"
    .ChartType = xlXYScatter
End With

'With NormPChart.Axes(xlCategory)
'.MinimumScale = ws.Range("AG13")
'.MaximumScale = ws.Range("AG72")
'End With

Can anyone please tell me why this graphs the number of data points instead of actual data values?