US universities retained their dominance in an annual Chinese ranking of the world’s top academic institutions, with Harvard staying No. 1 for the 15th straight year.

In the top 10, little changed from last year, Stanford held on to the second spot in the “Academic Ranking of World Universities” compiled by the independent Shanghai Ranking Consultancy, which has ranked the top 500 institutions each year since 2003.

A statement accompanying this year’s results said the rankings were based on a range of indicators including alumni and staff winning Nobel Prizes and Fields Medals, and papers published in the journals “Nature” and “Science.”

The University of Cambridge and the Massachusetts Institute of Technology each moved up a slot to take third and fourth as the University of California at Berkeley dropped two places to fifth position.