Attempt to reproduce the "frac" column of Tor Metrics CSV.

https://lists.torproject.org/pipermail/tor-dev/2022-April/014724.html
https://lists.torproject.org/pipermail/tor-dev/2022-April/014725.html
https://bugs.torproject.org/tpo/network-health/analysis/35

https://collector.torproject.org/archive/relay-descriptors/consensuses/consensuses-2022-04.tar.xz
https://collector.torproject.org/archive/relay-descriptors/extra-infos/extra-infos-2022-04.tar.xz

./relay_uptime.py consensuses-2022-04.tar.xz > relay_uptime.csv
./relay_dir.py extra-infos-2022-04.tar.xz > relay_dir.csv
./frac.py relay_uptime.csv relay_dir.csv
