The grade I was referring to was a grade by the Office of the Information Commissioner. The Information Commissioner does an annual review, and it's not just a grade. The last report had a letter grade, a star system, and also gave an overall assessment. For the year we just completed, we had 82% of our requests on time, and that would equate--if the commissioner uses the same criteria--to a C grade.
On June 1st, 2010. See this statement in context.