I would not retake it. That would be pretty pathetic if a school would turn you away with complete disregard to all those other great scores. I believe it would be different if you had that 15 with a bunch of 17s and 18s, but you are solid in my opinion. Additionally, you don't want to risk a decrease in the other sections if you did retake it. Declines never look good. I say enough with the speculation and call the academic affairs office of your school of interest and see for youself. You may be surprised