From FCW:
The Center for Effective Government on March 13 released a report on the government’s Freedom of Information Act response efforts, finding that agencies processed more FOIA in 2012 than in previous years, and that backlogs have declined even as the number of requests has grown. But more requests are being redacted, the report found, and the cost of FOIA processing varied widely from agency to agency.
The data “suggests there may some economies of scale in processing FOIA requests,” the report states, but volume alone does not explain the variations — the State Department spent more than four times as much to process each request as did the National Archives and Records Administration, which responded to roughly the same number of inquiries.