I am currently working on the umpteenth version of a query letter for a novel. Back in my senior year of high school, I self-published a book of short stories. I wrote it, had it edited, and then made many copies which I gave out to friends and family members. I never sold (or tried to sell) any copies of it. Should I mention that I self-published a book in my query letter, or is this likely to cause an agent to reflexively crumple my query letter into a ball and send it flying through the air into the recycle bin?
Let's think about this for a minute. First, is this writing that will HELP your career? Try to think objectively. Answer: most likely not. In fact I hope not cause I'm hoping you've improved rather dramatically as a writer in the however many years it's been since you Ruled The School as a Swaggering Senior (by the way, Grease the Musical has been banned in Fulton Missouri as "objectionable"...and here I thought all the kids were mounting productions of Rent).
The other thing is the agent can't actually check sales figures for a book you didn't sell, so it's meaningless. Agents are mercenary creatures. The reason we are interested in your "backlist" is to determine if you can write worth spit, and sell. We are not interested in checking your CV for initiative and community service as though you are applying to Yale.
Short answer: no, leave it off.