Percentage of countries with a sex difference in mathematics >0.

The average PISA score of all students in OECD countries is 500. A high percentage of the countries that have an overall mathematics score over 500 in mathematics have a sex difference in mathematics greater than zero (no country had a score of exactly 500). This occurs less frequently among the lower scoring countries, although the difference was negligible in 2003. Altogether, this shows that boys exceeding girls is more strongly associated with an overall high mathematics performance.