Binary files (arbitrary example: images used for golden screenshots in tests) have no line counts and are likely skewing the numbers here -- in the way you're (logically) looking to interpret them at least.

From a system design perspective, being able to handle a large number of files regardless of type is an interesting challenge, as is being able to handle a large number of highly indexed text files. All three of those statistics seem potentially interesting for different audiences that might read this paper.