My Turnitin essay was 48% plagiarism?

I went over it on turn it in, and it said 48% originality...so I looked it up and 34% of it was highlighted under my essay question, so that can be taken away, and at least 5-6% was supposedly other students work submitted...Im assuming my overall grade should have gone right down...but some internet soures could see where I attempted my own words. How much percentage would the teachers take into consideration?