We were relying on the GitHub API to estimate the age of the repo since it was created on GitHub. This led to some very old repos (e.g. Python itself) being included despite being 30 years old according to the Git logs.
We were using Pandas to calculate the average warning-frequency, but this dropped NA values. The notebooks were updated to treat NA counts (i.e. no warnings) as 0.
Notebooks previously contained two major bugs: