A study conducted in 2011 that involved more than 1000 medical schools throughout the world indicated on average, 64 university exams, 130 series exams, and 174 assignments are completed over the course of 5.5 years. Students need more than 85% marks in prerequisite courses in order to get enrolled for the aptitude test for these degree programs. They then have to pass the test with 85% to 90% marks, which is high compared with all the other bachelor's degree programs. The World Health Organization has granted international recognition to certain widely offered conventional medical degrees. Degrees recognized internationally by the AVICENNA Directory for medicine/International Medical Education Directory.