Starting from 2003, ARWU has been presenting the world Top 500 universities annually based on a set of objective indicators and third-party data. ARWU has been recognized as the precursor of global university rankings and the most trustworthy league table. ARWU adopts six objective indicators to rank world universities, including the number of alumni and staff winning Nobel Prizes and Fields Medals, the number of Highly Cited Researchers, the number of articles published in journals of Nature and Science, the number of articles indexed in Science Citation Index - Expanded and Social Sciences Citation Index, and per capita performance. About 1500 universities are actually ranked by ARWU every year and the best 500 universities are published. In 2018, those universities ranked between 501 and 1000 in the world are also published.