The count of contributions (summary of Pull Requests, opened issues and commits) to public repos at GitHub.com from Tue, 03 Dec 2013 07:25:57 GMT till Wed, 03 Dec 2014 07:25:57 GMT.
Only first 1000 GitHub users according to the count of followers and with more than a hundred repos are taken. This is because of limitations of GitHub search. Sorting algo in pseudocode:
githubUsers
.filter((user) -> user.followers > 101 & user.repos > 101)