Advanced Placement Exam scores are reported on a scale of 1 to 5, where a 5 is equivalent to grades of A+ and A in the corresponding college course. Brian received the top score of 5. Only 14.3 percent of the 3,939,100 exams taken in 2013 earned this top score. Brian was one of only eight students in the world to earn every point possible on the Calculus AB Exam, answering every multiple-choice question correctly and earning the maximum scores on each of the essays in the free-response section of the exam. In total, 283,361 students took the AP Calculus AB Exam in 2013.