Grace wants to attend University of Oklahoma. One year at University of Oklahoma costs approximately $20,000. She currently has $4,000 in savings. Grace has received a one-time grant of $1,000 and an annual academic scholarship for $4,000. She plans to enroll in the work study program that will pay $9,000 annually for part-time work. How much will Grace need to borrow in student loans in order to attend University of Oklahoma for 4 years?