Total percentage for a query

[Gregw]

I have the following query:

SELECT qry1.OrderYear AS OrderYear, qry1.OrderMonth AS OrderMonth,
qry1.CountofFileNumber AS FilesOpened, qry2.FilesClosed AS FilesClosed,
qry2.SumofGross AS SumofGross, (qry2.FilesClosed/qry1.CountofFileNumber) AS
[% Closed]
FROM qry1 LEFT JOIN qry2 ON (qry1.OrderMonth = qry2.CloseMonth) AND
(qry1.OrderYear = qry2.CloseYear)
ORDER BY qry1.OrderYear, qry1.OrderMonth;

which gives me the total number of orders for each month, total number of
orders closed in each month, and a percentage of files ordered vs. closed.
Is there a easy way to sum up all the "% Closed" and get an average by year
or an overall average?

Thanks for the help