Ashkenazi Jews have a noted history of achievement in Western societies in the fields of exact and social sciences, literature, finance, politics, media, and others. In those societies where they have been free to enter any profession, they have a record of high occupational achievement, entering professions and fields of commerce where higher education is required. Ashkenazi Jews have won a large number of the Nobel awards. While they make up about 2% of the U.S. population, 27% of United States Nobel prize winners in the 20th century, a quarter of Fields Medal winners, 25% of ACM Turing Award winners, half the world's chess champions, including 8% of the top 100 world chess players, and a quarter of Westinghouse Science Talent Search winners have Ashkenazi Jewish ancestry.