Think of it as resetting the button once you graduated from hs.
I would list all all the years. I think it shows that your involvement with the community isn't just because it's a requirement for the application. In fact at a dental interview a topic came up that involved a large amount of community service for church I had done about 15 years earlier. My interviewer asked my why I hadn't listed it on my application. I told him it had been so many years ago I didn't think about it. He told me if I have to apply again to make sure I list it.
Skip the HS stuff. We are interested in what you were capable of doing while maintaining a college course load, not HS course load..