Exporting Gridview to Excel that has subtotals

Question

I have a gridview that I can export to excel.  I have added subtotals to my gridview, but now when I export the data to excel, not all the data is coming over.    The count for the gridview is not incrementing when I add subtotals.  So only the original number of lines in the gridview are exporting to excel.   How can I fix this?