I wonder if someone could tell me which formula to use to do the following:

A1= the sum of the yes responses from each sales rep in a quarter (Jan-Mar)

Month SalesRep Response
Jan John No
Feb John Yes
Mar Bill Yes
Apr John No

Answer = 1 yes response for JOHN in the first quarter (jan-Mar)

Answer = 1 yes response for Bill in the first quarter

I am using name ranges .i.e Month SalesRep Response

Thank you in advance for any help you can provide
Ferde