Must I include my high school GPA on my resume for a work-study job in my upcoming first year of college?

My GPA isn't bad, but it just isn't something I would brag about, especially since it's on the low end in comparison to the GPAs of people who were accepted to the college I'll be attending in a few months. If I have to include it, can I point out my upward trend? I went from a 2.8 GPA in 9th and 10th grade to a 4.5 in my junior and senior years.