Average is clever enough to ignore empty cells so why not
=AVERAGE(A:A)
--
Mike
When competing hypotheses are otherwise equal, adopt the hypothesis that
introduces the fewest assumptions while still sufficiently answering the
question.
If you want to include every new row in the average formula, then you may
convert the range to a List/Table (Ctrl+T). Select the entire range
(including the header row) and press Ctrl+T. When you convert a range to a
Table, it auto expands in every formula in which the range ie being used in
the workbook