The Instituto Cervantes publishes the results approximately three months after the examination, upon the approval of grades by the University of Salamanca.[22] Participants need to pass all parts of the exam in order to pass the entire test. The average passing rate including all levels was 61% in 2012; but the passing rate decreased significantly with the increased difficulty from A1, where the passing rate was higher than 75%, to C2 level, where more than half of the participants failed the test.[23] The results are permanently valid.[1] The C2 exam is considered by some to be the most difficult official Spanish language exam available.