If you have been arrested before and you are filling out an application, do you have to note that you have?

I am filling out an application to volunteer at a local hospital. I have been convicted of a DUI, it was my second, but I do not know if it is considered a crime. The question on the application is: Have you ever been convicted of, or plead guilty to, a crime within or outside the state of….

Do I have to mark yes? I have plead guilty to a DUI charge. Any help is greatly needed. Thank you. Also, please no comments like you are so stupid, never drink and drive blah blah blah! I’ve heard it all and have certainly learned from it and have changed my ways.