How do I expand on my volunteer service?

I’m a homeschooled high school senior, and I plan on majoring in Elementary Education (most likely ELA instruction), and over the course of four years, I’ve spent around 380 hours tutoring children with special needs in grades 2-7 in ELA and math. I’m very passionate about this EC, and I sit in on board meetings, tutoring meetings, and I play a major part in planning events like Halloween and Christmas parties for the students who attend the tutoring service. However, I can’t find a way to elaborate on this, and the only way I can put it is volunteering for 6 hours a week, 36 weeks a year through Common App.

In my opinion, this seems very weak and understated. How can I show colleges that I was very dedicated to this position and I plan on continuing this through college?