Over 95% of B-schools worldwide look at your BEST GMAT SCORE across all your GMAT attempts in the last 5 years. In the event that your latest GMAT score is not your best score (an earlier attempt had a better score), they will still consider your higher score. Very few B-schools average out the scores
Do also remember that almost 50% of applicants to top b-schools submit more than one GMAT score while applying for the MBA program.