Singular And Plural Adgroups in Yahoo

Hi everyone,

I am about to start advertising on Yahoo and I have a question.

In my Adwords campaign I usually divide the singular and plural forms of my keywords in different adgroups, since they usually convert at different levels (and I want to be able to change my bids accordingly).

I know that Yahoo automatically displays my ad for the singular AND plural version of a keyword, no matter which kind of match option I choose.

My question is: if I create separated adgroups for the singular and plural forms of a keyword, will Yahoo divide the clicks and conversion stats between the two or simply report everything under one of the two adgroups (effectively ignoring the difference between singular and plural)?

Thanks for your insight!