Past data, no. It's not actively logged anywhere.

Cockpit has a network history feature.

There are many options, but you have to search for network graphs ...

Here are some names that come off the top of my head:

MRTG - a classic, serves as basis for many other tools. Can monitor anything that has SNMP and if you do some scripting also things without SNMP.

Cacti - a bit more evolute than the above, but same concept.

LibreNMS - this one uses a database for storing data. Can monitor network elements as well as servers. Nice graphs. There's no .deb but it's easy to install.

Prometheus - this can monitor a lot of things, you will need a graphing front end to get the most of it.

Grafana - coupled with Prometheus or any other modern data collection tool it's a very powerful graphing and reporting tool. A bit daunting maybe, it requires some learning.

There are many others, some generic, some specialized. Pick one and try it, if you don't like the results there's plenty of choices. A VM will help with not cluttering your server.

For a simple way to do what you want, you can use vnstat. It can give you totals per interface, hour, day, week, month, etc.

Of course it can only show figures captured after it was installed.

Thanks everyone! Will be checking these out.