The count of contributions (summary of Pull Requests, opened issues and commits) to public repos at GitHub.com from Wed, 14 Aug 2013 05:10:53 GMT till Thu, 14 Aug 2014 05:10:53 GMT.
Only first 1000 GitHub users according to the count of followers are taken. This is because of limitations of GitHub search. Sorting algo in pseudocode:
githubUsers .filter((user) -> user.followers > 296)