[tor-talk] where can I find specification document for Tor Metrics?

[Anonymous Kyoto]

Hi friends,
I read this page https://metrics.torproject.org/about.html, and there is a
sentence:
<all raw numbers are available in comma-separated value files (.csv), which
have their own specification document.>
But when I click the hyperlink, the file in this link
https://gitweb.torproject.org/metrics-web.git/tree/doc/stats-spec.txt
contains nothing.
Please help.