My thought process is if you have done a lot of great thigns go ahead and describe them in detail.
I set up a lot of small things and made the relationships with our school, and turned it into a yearly event, but still i only did them once. In this case, less is more. If you don't put hours, you won't be selling yourself short and won't be lieing. It may be A overlooked as oh wow he did a lot or B a topic of conversation at an interview where you can get into the knitty gritty and fluff it up a little perhaps tell a story if your good with interviews.