You can see all commits made to a repository in the past year (excluding merge commits) in the Commit graph.
This repository insights graph is available in public repositories with GitHub Free and GitHub Free for organizations, and in public and private repositories with GitHub Pro, GitHub Team, GitHub Enterprise Cloud, and GitHub Enterprise Server. For more information, see "About repository graphs" and "GitHub's products."
The top graph shows commits for the entire year by week.
The bottom graph shows the average number of commits by day of the week for the selected week.