Is there a quick, easy way in Excel to do subtotals ever certain number of
rows? In my case I need subtotals every 15 rows. Oh, this is Excel 2003.

I know how to use the Subtotals tool but the only option there seems to be
subtotals based on the change in values of a column. In my case I don't care
about the values of any columns, I just need the subtotals every 15 rows.

Of course I could do this manually, but I'm hoping there's a quick and easy
way to do it similar to how the built-in Subtotals tool works.

Thank you.