I'm not even sure where to find the code for http://gerrit-stats.wmflabs.* *org/ http://gerrit-stats.wmflabs.org/ . In gerrit I could only find the /analytics/scorecard project.
The repo is available at: https://gerrit.wikimedia.org/r/gitweb?p=analytics%2Fgerrit-stats.git;a=short... As mentioned before, Limn is responsible for visualizing the data, gerrit-stats only pulls data from Gerrit and construct measures. Happy to discuss how to come up with developer centric measures.
Best, Diederik