I'm drawing a blank on how to do this. I need a formula to count "Yes"
values per unique value in another colum. (see example)

In each record...
The first column (A) shows trip codes.
The second column (B) shows either "Yes" or blank.

I need a formula that counts all "Yes" values in column B per trip
code.

For example, using the data below, "2" would be the answer because 2
trip codes corresponded to "Yes".

Trip Covered
tr-24 Yes
tr-24 Yes
tr-24 Yes
tr-50
tr-50
tr-16 Yes
tr-16 Yes
tr-16 Yes
tr-16 Yes

It might help to know when "Yes" appears in a record of a particular trip
code,
it appears in each record of that code. No mixing.

Excel 2002

Thanks for your help!