Excel 2007 : Countif

Sorry, I didn't explain this very well and am attaching a sample file. This is a mailing to customers done periodically throughout the year. The dates in column A are the dates each mailing is sent and the response to those mailings (if any) is in column B (I = request for more info., Z = not interested, R = request a salesman call).

We want to determine if the time of year we do a mailing has any influence of the responses (i.e. do we get a higher response rate to mailings done in the fall versus right around Christmas). So the blank boxes in column E through L are supposed to count the occurrences of I, Z, and R by the unique date shown above it. Note that in Col A there are multiple instances of the same date (each date represents a specific customer) but that in E through L there is only one unique date, under which the counts should be shown.

I hope this makes things a little clearer. Thanks for your response so far.