Your period for the one agency you used will be Sep 1 2005 to Aug 31 2006. It's a rolling 12-month period from your most recent request. So if you make your next request on, say, Oct 20 2006; that will lock out the 12-month period from Oct 20 2006 to Oct 19 2007.

The clock runs separately for each agency, so you can get the reports at 4-month intervals like you say. (And you can always get the first agency's report again if you really want; you'll just have to pay for it.)

- Erik