Retake TOEFL?

Hey guys…
I’m new in this website. I studied computer science last summer at the University of Pennsylvania. I’m applying for admission for Fall 2016. I just took the TOEFL and I got a 100, which is the minimum recommended score. Also, their website states that many accepted applicants score around 105-112. Should I retake it just to improve 3-5 points? (I got a 31 in ACT English)

I wouldn’t retake it; it’s too expensive. It’s just a cut-off score.