Calculating Accuracy % from a list of data

Newbie with Excel.

I've created a spreadsheet which I've attached. It shows the results of QC pass/fail (Col E) for various processors (Col A).

What I would like the report to do is show an Accuracy % by Examiner(Col A) and Date(Col C). Where Accuracy % = (Count of rows where Col E = No Error / Count of all rows matching the selected Examiner and Date).

Something like this:
Examiner......................Date(drop-down).....Accuracy%
Joe Smith.......................July 2009.................100%
Nancy Smith...................July 2009.................90%

If this can be accomplished on a separate tab that would be great so as not to affect the raw data tab which people will be entering data on.

I have some other reports I need to build as well, but I think if I can understand how to setup this first one, I can run with the others.

Thanks for all replies!