qnli question: About how many Fields Medal winners have been Ashkenazi Jews? sentence: 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.