Due to GitHub's nature, a repository contains many metadata such as commits over time, who contributed what, number of contributors, number of forks, and even site referrals to various files.
GitHub provides some useful graphs and data from which you can deduct the information you require.
Graphs can be accessed through the right sidebar of a repository:
To better understand how this works, pick up a project with high traffic; for example, https://github.com/twbs/bootstrap/graphs. The default tab is the Contributors tab and also the one we will explore next.
An overview of the top 100 contributors of a project can be seen at the Contributors tab. The graph is created by the data of the default branch of a repository and it depicts the commits from the beginning of the project until the current day:
At the bottom there are the statistics of the total number of commits, along with the line additions and deletions of each of the top 100 contributors...