Some notes on these.
For a lot of early years I just lack access to the code bases I was working on. In addition some older version control systems (cvs and subversion) didn’t make branching super easy, so commits tended to be less frequent.
Starting from around 2017, the activity data includes more than just code - activity on tickets, merge requests and some other events show up.
In future revisions of this it might be nice to have the summarizing step add some context to where the data is coming from. It might also be interesting to pull from other sources. Sent emails, calendars, etc.