The metrics in this gist come from Mercurial. They are produced with the help of the mozext extension, which can be obtained at https://hg.mozilla.org/hgcustom/version-control-tools/file/default/hgext/mozext.
See http://gregoryszorc.com/blog/2013/11/08/using-mercurial-to-query-mozilla-metadata/ for usage info.
$ hg log -r 'tree(central) and not merge() and firstpushdate("2013")' --template '{author}n' | sort | uniq -c | sort -n
$ hg log -r 'tree(central) and not merge() and firstpushdate("2013")' --template '{join(reviewers, "n")}n' | sort | uniq -c | sort -n
Please note that the reviewer parsing code in mozext is not super robust at the moment. There will be many weird entries. If you would like to improve the parsing code, you can find it at https://bitbucket.org/indygreg/python-mozautomation/src/default/mozautomation/commitparser.py?at=default. Chances are high that the reviewer counts are very wrong as a result.